Color Vision Deficiency, Colour Blindness, Impaired Color Vision
If you have color blindness, you'll see colors differently than others and will have difficulty seeing the difference between certain colors. It's usually genetic and is more common in men. Learn about genetic factors and how to adjust if you are color blind.
Eye Colors and Color Blindness
Image by PublicDomainPictures
Color Blindness
"Color Blindness" Deuteranomaly demonstration Color Blindness, Anomalous Color Vision
Image by Johannes Ahlmann
"Color Blindness" Deuteranomaly demonstration Color Blindness, Anomalous Color Vision
On the left two pictures as seen by a person with "normal" vision. On the right, the same pictures simulated as seen by a person with deuteranomaly i.e. limited red/green distinction.
Image by Johannes Ahlmann
Color Blindness
Most of us see our world in color. We enjoy looking at a lush green lawn or a red rose in full bloom. If you have a color vision defect, you may see these colors differently than most people.
There are three main kinds of color vision defects. Red-green color vision defects are the most common. This type occurs in men more than in women. The other major types are blue-yellow color vision defects and a complete absence of color vision.
Most of the time, color blindness is genetic. There is no treatment, but most people adjust and the condition doesn't limit their activities.
Source: National Eye Institute (NEI)
Additional Materials (23)
Simulation of Different Color Deficiencies, Color Blindness
Simulation of Different Color Deficiencies, Color Blindness
"normal" color vision
green-blindness (deuteranopia)
red-blindness (protanopia)
blue-blindness (tritanopia)
Image by Johannes Ahlmann
Color Vision 1: Color Basics
Video by Craig Blackwell/YouTube
Ask a Scientist: What Is Color Blindness?
Video by National Eye Institute, NIH/YouTube
Is there a Cure for Color Blindness?
Video by Contact Lens King/YouTube
Are You Color Blind? (the quick brain test with answers)
This Is What Color Blind People See With These Viral Glasses
Tech Insider/YouTube
2:35
How Many Colors Can We See?
SciShow/YouTube
2:47
Colorblind - A Colorful Guide to Colorblindness (infographic) V1
gleiberkid/YouTube
3:31
How Does Colorblindness Work?
BrainStuff - HowStuffWorks/YouTube
3:32
How Vision Tests Work | Living Healthy Chicago
LivingHealthyChicago/YouTube
1:45
Cornea - Human Eye
Alternate Learning/YouTube
9:03
Inheritance of X-Linked Genes
Professor Dave Explains/YouTube
What Is Color Blindness?
Ishihara 1
Image by Nicoguaro/Wikimedia
Ishihara 1
Ishihara Plate No. 1 (Number 12). Used to for the en:Ishihata test of color blindness.
Image by Nicoguaro/Wikimedia
What Is Color Blindness?
If you have color blindness, it means you see colors differently than most people. Most of the time, color blindness makes it hard to tell the difference between certain colors.
Usually, color blindness runs in families. There’s no cure, but special glasses and contact lenses can help. Most people who are color blind are able to adjust and don’t have problems with everyday activities.
Source: National Eye Institute (NEI)
Additional Materials (2)
Ask a Scientist: What Is Color Blindness?
Video by National Eye Institute, NIH/YouTube
How Color Blindness Works
Video by Human Interests/YouTube
1:56
Ask a Scientist: What Is Color Blindness?
National Eye Institute, NIH/YouTube
6:44
How Color Blindness Works
Human Interests/YouTube
Color Vision
Color blindness Normal Vision
Deuteranopia sight
Tritanopia color-blind
Monochromacy sight
1
2
3
4
Color Blindness 1) Normal Vision 2) Deuteranopia sight 3) Tritanopia sight 4) Monochromacy sight
Interactive by Wikipedia
Color blindness Normal Vision
Deuteranopia sight
Tritanopia color-blind
Monochromacy sight
1
2
3
4
Color Blindness 1) Normal Vision 2) Deuteranopia sight 3) Tritanopia sight 4) Monochromacy sight
Color Blindness 1) Normal Vision 2) Deuteranopia sight 3) Tritanopia sight 4) Monochromacy sight
Interactive by Wikipedia
Color Vision
Color Vision
Normal-sighted individuals have three different types of cones that mediate color vision. Each of these cone types is maximally sensitive to a slightly different wavelength of light. According to the trichromatic theory of color vision, shown in the Figure below, all colors in the spectrum can be produced by combining red, green, and blue. The three types of cones are each receptive to one of the colors.
This figure illustrates the different sensitivities for the three cone types found in a normal-sighted individual. (credit: modification of work by Vanessa Ezekowitz)
The trichromatic theory of color vision is not the only theory—another major theory of color vision is known as the opponent-process theory. According to this theory, color is coded in opponent pairs: black-white, yellow-blue, and green-red. The basic idea is that some cells of the visual system are excited by one of the opponent colors and inhibited by the other. So, a cell that was excited by wavelengths associated with green would be inhibited by wavelengths associated with red, and vice versa. One of the implications of opponent processing is that we do not experience greenish-reds or yellowish-blues as colors. Another implication is that this leads to the experience of negative afterimages. An afterimage describes the continuation of a visual sensation after removal of the stimulus. For example, when you stare briefly at the sun and then look away from it, you may still perceive a spot of light although the stimulus (the sun) has been removed. When color is involved in the stimulus, the color pairings identified in the opponent-process theory lead to a negative afterimage. You can test this concept using the flag in the Figure below.
Stare at the white dot for 30–60 seconds and then move your eyes to a blank piece of white paper. What do you see? This is known as a negative afterimage, and it provides empirical support for the opponent-process theory of color vision.
But these two theories—the trichromatic theory of color vision and the opponent-process theory—are not mutually exclusive. Research has shown that they just apply to different levels of the nervous system. For visual processing on the retina, trichromatic theory applies: the cones are responsive to three different wavelengths that represent red, blue, and green. But once the signal moves past the retina on its way to the brain, the cells respond in a way consistent with opponent-process theory (Land, 1959; Kaiser, 1997).
CONNECT THE CONCEPTS
Colorblindness: A Personal Story
Several years ago, I dressed to go to a public function and walked into the kitchen where my 7-year-old daughter sat. She looked up at me, and in her most stern voice, said, “You can’t wear that.” I asked, "Why not?" and she informed me the colors of my clothes did not match. She had complained frequently that I was bad at matching my shirts, pants, and ties, but this time, she sounded especially alarmed. As a single father with no one else to ask at home, I drove us to the nearest convenience store and asked the store clerk if my clothes matched. She said my pants were a bright green color, my shirt was a reddish orange, and my tie was brown. She looked at my quizzically and said, "No way do your clothes match." Over the next few days, I started asking my coworkers and friends if my clothes matched. After several days of being told that my coworkers just thought I had "a really unique style," I made an appointment with an eye doctor and was tested (Figure). It was then that I found out that I was colorblind. I cannot differentiate between most greens, browns, and reds. Fortunately, other than unknowingly being badly dressed, my colorblindness rarely harms my day-to-day life.
The Ishihara test evaluates color perception by assessing whether individuals can discern numbers that appear in a circle of dots of varying colors and sizes.
Some forms of color deficiency are rare. Seeing in grayscale (only shades of black and white) is extremely rare, and people who do so only have rods, which means they have very low visual acuity and cannot see very well. The most common X-linked inherited abnormality is red-green color blindness (Birch, 2012). Approximately 8% of males with European Caucasian decent, 5% of Asian males, 4% of African males, and less than 2% of indigenous American males, Australian males, and Polynesian males have red-green color deficiency (Birch, 2012). Comparatively, only about 0.4% in females from European Caucasian descent have red-green color deficiency (Birch, 2012).
Source: CNX OpenStax
Additional Materials (7)
Color Vision 6: Color with 1, 2 or 3 Cones. In Humans and Various Animals.
Video by Craig Blackwell/YouTube
Color Vision 4: Cones to See Color
Video by Craig Blackwell/YouTube
Color Vision 1: Color Basics
Video by Craig Blackwell/YouTube
Color Vision 8: Opsins and the Evolution of Color Vision
Video by Craig Blackwell/YouTube
Color Vision 7: Primate Color Vision
Video by Craig Blackwell/YouTube
Color Vision 2: Color Matching
Video by Craig Blackwell/YouTube
Cone Mosaics
Illustration of the distribution of cone cells in the fovea of a individual with normal color vision (left), and a color blind (protanopic) retina. Note that the center of the fovea holds very few blue-sensitive cones.
Image by Mark Fairchild
18:15
Color Vision 6: Color with 1, 2 or 3 Cones. In Humans and Various Animals.
Craig Blackwell/YouTube
17:19
Color Vision 4: Cones to See Color
Craig Blackwell/YouTube
15:11
Color Vision 1: Color Basics
Craig Blackwell/YouTube
11:19
Color Vision 8: Opsins and the Evolution of Color Vision
Craig Blackwell/YouTube
17:25
Color Vision 7: Primate Color Vision
Craig Blackwell/YouTube
20:58
Color Vision 2: Color Matching
Craig Blackwell/YouTube
Cone Mosaics
Mark Fairchild
Types
Democratic Primary Process Map Color Blindness Simulation
Image by Infoporfin at English Wikipedia
Democratic Primary Process Map Color Blindness Simulation
Democratic Primary Process Map Color Blindness Simulation
Image by Infoporfin at English Wikipedia
Types of Color Blindness
Having color blindness means you can’t see certain colors the way most people do — or you may not see color at all.
The most common type of color blindness makes it hard to tell the difference between red and green.
There are 4 types of red-green color blindness:
Deuteranomaly is the most common type of red-green color blindness. It makes green look more red. This type is mild and doesn’t usually get in the way of normal activities.
Protanomaly makes red look more green and less bright. This type is mild and usually doesn’t get in the way of normal activities.
Protanopia and deuteranopia both make you unable to tell the difference between red and green at all.
If you have complete color blindness, you can’t see colors at all. This is also called monochromacy, and it’s quite uncommon. Depending on the type, you may also have trouble seeing clearly and you may be more sensitive to light.
Source: National Eye Institute (NEI)
Additional Materials (4)
Red-green colour blindness, do you have it?
Video by Demystifying Medicine/YouTube
The Science of Color Blindness
Video by Life Noggin/YouTube
Color blindness
A comparison of the visible color spectrum in common types of color blindness.
Image by Nanobot
Perception of color by subjects affected by different types of color blindness.
Perception of color by subjects affected by different types of color blindness.
Image by Japs 88
6:29
Red-green colour blindness, do you have it?
Demystifying Medicine/YouTube
2:51
The Science of Color Blindness
Life Noggin/YouTube
Color blindness
Nanobot
Perception of color by subjects affected by different types of color blindness.
Japs 88
Risk Factors
Family History and being Caucasian put you at higher risk for AMD
Image by PublicDomainPictures
Family History and being Caucasian put you at higher risk for AMD
Family History and being Caucasian put you at higher risk for AMD
Image by PublicDomainPictures
Am I at Risk for Color Blindness?
Men have a much higher risk than women for color blindness. You’re also more likely to have color blindness if you:
Have a family history of color blindness
Have certain eye diseases, like glaucoma or age-related macular degeneration (AMD)
Have certain health problems, like diabetes, Alzheimer’s disease, or multiple sclerosis (MS)
Take certain medicines
Are white
If you think you may have color blindness, talk with your doctor about getting checked.
Source: National Eye Institute (NEI)
Additional Materials (2)
How Color Blindness Works
Video by Human Interests/YouTube
Chromosome X&Y (23) - Colour Blindness
Video by The Royal Institution/YouTube
6:44
How Color Blindness Works
Human Interests/YouTube
2:23
Chromosome X&Y (23) - Colour Blindness
The Royal Institution/YouTube
Causes
Punnett square colour blindness
Image by Cmglee
Punnett square colour blindness
Punnett squares for each combination of parents' colour vision status giving probabilities of their offsprings' status, each cell having 25% probability in theory.
Image by Cmglee
Causes of Color Blindness
Having color blindness means you can’t see certain colors the way most people do — or you may not see color at all.
What causes color blindness?
The most common kinds of color blindness are genetic, meaning they’re passed down from parents. If your color blindness is genetic, your color vision will not get any better or worse over time.
Conditions like color blindness are passed from parents to their children on groups of genes called chromosomes.
Some of these, called X and Y chromosomes, determine if you are male or female at birth. Males have 1 X chromosome and 1 Y chromosome, and females have 2 X chromosomes. The genes that can give you red-green color blindness are passed down on the X chromosome.
Since it’s passed down on the X chromosome, red-green color blindness is more common in men. This is because:
Males have only 1 X chromosome, from their mother. If that X chromosome has the gene for red-green color blindness (instead of a normal X chromosome), they will have red-green color blindness.
Females have 2 X chromosomes, one from their mother and one from their father. To have red-green color blindness, both X chromosomes would need to have the gene for red-green color blindness.
Blue-yellow color blindness and complete color blindness are passed down on other chromosomes, so they affect males and females equally.
What diseases or injuries can cause color blindness?
Color blindness can also happen if your eyes or the part of your brain that helps you see color gets damaged. This can be caused by:
Eye diseases, like glaucoma or macular degeneration
Brain and nervous system diseases, like Alzheimer’s or multiple sclerosis
Some medicines, like Plaquenil (a rheumatoid arthritis medicine)
Eye or brain injuries
Your color vision may also get worse as you get older, especially if you get a cataract — a cloudy area on your eye.
Source: National Eye Institute (NEI)
Additional Materials (2)
What Causes Color Blindness?
Video by Seeker/YouTube
X-linked recessive
X-linked recessive inheritance scenarios for either the mother being a carrier or the father being affected
Image by Domaina, Kashmiri and SUM1
3:46
What Causes Color Blindness?
Seeker/YouTube
X-linked recessive
Domaina, Kashmiri and SUM1
Symptoms
Protanopia - Color Blindness Deficiency
Image by Albarubescens
Protanopia - Color Blindness Deficiency
Color Blindness Deficiency
Image by Albarubescens
What Are the Symptoms of Color Blindness?
The main symptom of color blindness is not seeing colors the way most people do. If you’re color blind, you may have trouble seeing:
The difference between colors
How bright colors are
Different shades of colors
Symptoms of color blindness are often so mild that you may not notice them. And since we get used to the way we see colors, many people with color blindness don’t know they have it.
People with very serious cases of color blindness might have other symptoms, too — like quick side-to-side eye movements (nystagmus) or sensitivity to light.
Source: National Eye Institute (NEI)
Additional Materials (1)
What It's Like To Be Color Blind
Video by BuzzFeed Multiplayer/YouTube
2:38
What It's Like To Be Color Blind
BuzzFeed Multiplayer/YouTube
Testing
Rough gray and white representation of a test chart so that people with complete color blindness can also get an impression of the test.
Image by Barbarossa at Dutch Wikipedia/Wikimedia
Rough gray and white representation of a test chart so that people with complete color blindness can also get an impression of the test.
Image by Barbarossa at Dutch Wikipedia/Wikimedia
Testing for Color Blindness
Having color blindness means you can’t see certain colors the way most people do — or you may not see color at all.
If color blindness runs in your family, or if you think you or your child may have color blindness, talk to your eye doctor. They can give you or your child a simple vision test to check for color blindness.
Usually, your doctor can tell if you have color blindness from a test called the color plate test. If those results aren’t clear, there are other tests the eye doctor can do. You don’t have to wait for results for these tests — your eye doctor will be able to tell you if you have color blindness as soon as you take them.
Color plate test
This is the most common type of color blindness test. Your eye doctor will ask you to look at an image made up of colored dots with a differently colored number or shape in the middle. If the shape blends into the background and you can’t see it, you may have a type of color blindness. Different color plates can check for different types of color blindness.
Anomaloscope test
This test will check if you can match the brightness of two lights. You will look into an eyepiece at 2 lights that have different levels of brightness. You’ll use knobs to adjust the lights and try to get them to match. If you aren’t able to match the brightness of the 2 lights, you may have color blindness.
Hue test
In a hue test, you’ll get blocks that are different colors. Your eye doctor will have you arrange them in rainbow order, like from red to purple. If you have trouble putting them in the correct order, you may have a type of color blindness. Eye doctors often use this test for people who need to have very accurate color vision for their jobs — like photographers or designers.
Source: National Eye Institute (NEI)
Additional Materials (8)
Bilateral achromatopsia vs. normal vision
Left side Black and White. Right side 2×3 grid of squares colored with the primary and secondary colors of the RYB color model. Each tile has an ellipse colored complementary to the square that it’s in.
Image by Ellywa
Colorblind - A Colorful Guide to Colorblindness (infographic) V1
Video by gleiberkid/YouTube
RGB scheme contrast of complementary colors
2x3 grid with the ground colors of the RGB color model in the left squares and the right ellipses and their respective complementary color in thr RGB color model in the model on the left ellipses and the right squares.
Image by Ellywa (template) and Zupanto (uploader) (this version).
Face of Defense: Colorblind Airman Overcomes Hurdles to Succeed as Artist
Air Force Tech. Sgt. Juan Hernandez, 731st Air Mobility Squadron air terminal operations center senior information controller, looks through his sketch book on Osan Air Base, South Korea, Dec. 3, 2015. Hernandez learned early on that he could not see many colors on the electromagnetic spectrum, but he still became a self-taught artist. U.S. Air Force photo illustration by Senior Airman Kristin High
Image by Senior Airman Kristin High
Color schemes when viewed by color-blind people
This is a simulation of what color-blind people see WPTC color schemes.
From top left to bottom right:
Protanopia,Deuteranopia,Tritanopia,Achromatopsia
Protanomaly,Deuteranomaly,Tritanomaly,Achromatomaly
Image by Krit-tonkla/Wikimedia
Red/Green "Seven" Chart
For example, mild forms of red/green color blindness are very common, resulting only in the inability to tell apart shades of red and green. The gene for this trait is located on the X-chromosome. A mother who carries this recessive trait has normal red/green vision. Any of her sons who inherit the X-chromosome that carries this trait -- the allele for color blindedness -- will be mildly red/green color blind. In this chart used to test for color-blindedness, people with normal color vision can see the number seven. People with red/green color blindness cannot see the number seven.
Image by National Eye Institute
Colorblindness
Image by w:en:User:Limbicsystem
Colorblindness
An Ishihara test image as seen by subjects with normal color vision and by those with a variety of color deficiencies.
Image by Eddau processed File:Ishihara 2.svg by User:Sakurambo,
Bilateral achromatopsia vs. normal vision
Ellywa
2:47
Colorblind - A Colorful Guide to Colorblindness (infographic) V1
gleiberkid/YouTube
RGB scheme contrast of complementary colors
Ellywa (template) and Zupanto (uploader) (this version).
Face of Defense: Colorblind Airman Overcomes Hurdles to Succeed as Artist
Senior Airman Kristin High
Color schemes when viewed by color-blind people
Krit-tonkla/Wikimedia
Red/Green "Seven" Chart
National Eye Institute
Colorblindness
w:en:User:Limbicsystem
Colorblindness
Eddau processed File:Ishihara 2.svg by User:Sakurambo,
Testing Your Child
Doctors use a slit-lamp exam to look for eye defects.
Image by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Doctors use a slit-lamp exam to look for eye defects.
During a slit-lamp exam, a doctor will use a special light to look for eye defects, such as a white or gray-white ring on the cornea.
Image by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
When to Get Your Child Tested for Color Blindness
It can be tricky to diagnose color blindness in children. Kids who are color blind might try to hide it. But being color blind can make it harder to read off a chalkboard or do other activities, so it’s important to get your child tested if you’re concerned.
Get your child tested if they have a family history of color blindness or if they seem to be having trouble learning colors.
Ask your child’s eye doctor to test them. You also may be able to get your child tested at school.
Also called: Color Blindness Test, Color Perception Test, Ishihara Color Test
Eye care professionals use a variety of tests to diagnose color blindness. These tests can quickly diagnose specific types of color blindness. People with color blindness aren’t aware of differences among colors that are obvious to the rest of us.
Color Vision Testing
Also called: Color Blindness Test, Color Perception Test, Ishihara Color Test
Eye care professionals use a variety of tests to diagnose color blindness. These tests can quickly diagnose specific types of color blindness. People with color blindness aren’t aware of differences among colors that are obvious to the rest of us.
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Use the slider below to see how your results affect your
health.
Your result is Normal.
You should be able to distinguish between all colors.
Related conditions
Most of us share a common color vision sensory experience. Some people, however, have a color vision deficiency, which means their perception of colors is different from what most of us see. The most severe forms of these deficiencies are referred to as color blindness. People with color blindness aren’t aware of differences among colors that are obvious to the rest of us. People who don’t have the more severe types of color blindness may not even be aware of their condition unless they’re tested in a clinic or laboratory.
Inherited color blindness is caused by abnormal photopigments. These color-detecting molecules are located in cone-shaped cells within the retina, called cone cells. In humans, several genes are needed for the body to make photopigments, and defects in these genes can lead to color blindness.
There are three main kinds of color blindness, based on photopigment defects in the three different kinds of cones that respond to blue, green, and red light. Red-green color blindness is the most common, followed by blue-yellow color blindness. A complete absence of color vision —total color blindness – is rare.
Eye care professionals use a variety of tests to diagnose color blindness. These tests can quickly diagnose specific types of color blindness.
The Ishihara Color Test is the most common test for red-green color blindness. The test consists of a series of colored circles, called Ishihara plates, each of which contains a collection of dots in different colors and sizes. Within the circle are dots that form a shape clearly visible to those with normal color vision, but invisible or difficult to see for those with red-green color blindness.
The newer Cambridge Color Test uses a visual array similar to the Ishihara plates, except displayed on a computer monitor. The goal is to identify a C shape that is different in color from the background. The “C” is presented randomly in one of four orientations. When test-takers see the “C,” they are asked to press one of four keys that correspond to the orientation.
The anomaloscope uses a test in which two different light sources have to be matched in color. Looking through the eyepiece, the viewer sees a circle. The upper half is a yellow light that can be adjusted in brightness. The lower half is a combination of red and green lights that can be mixed in variable proportions. The viewer uses one knob to adjust the brightness of the top half, and another to adjust the color of the lower half. The goal is to make the upper and lower halves the same brightness and color.
The HRR Pseudoisochromatic Color Test is another red-green color blindness test that uses color plates to test for color blindness.
The Farnsworth-Munsell 100 Hue Test uses a set of blocks or pegs that are roughly the same color but in different hues (shades of the color). The goal is to arrange them in a line in order of hue. This test measures the ability to discriminate subtle color changes. It is used by industries that depend on the accurate color perception of its employees, such as graphic design, photography, and food quality inspection.
The Farnsworth Lantern Test is used by the U.S. military to determine the severity of color blindness. Those with mild forms pass the test and are allowed to serve in the armed forces.
The most common types of color blindness are inherited. They are the result of defects in the genes that contain the instructions for making the photopigments found in cones. Some defects alter the photopigment’s sensitivity to color, for example, it might be slightly more sensitive to deeper red and less sensitive to green. Other defects can result in the total loss of a photopigment. Depending on the type of defect and the cone that is affected problems can arise with red, green, or blue color vision.
Red-green color blindness
The most common types of hereditary color blindness are due to the loss or limited function of red cone (known as protan) or green cone (deutran) photopigments. This kind of color blindness is commonly referred to as red-green color blindness.
Protanomaly: In males with protanomaly, the red cone photopigment is abnormal. Red, orange, and yellow appear greener and colors are not as bright. This condition is mild and doesn’t usually interfere with daily living. Protanomaly is an X-linked disorder estimated to affect 1 percent of males.
Protanopia: In males with protanopia, there are no working red cone cells. Red appears as black. Certain shades of orange, yellow, and green all appear as yellow. Protanopia is an X-linked disorder that is estimated to affect 1 percent of males.
Deuteranomaly: In males with deuteranomaly, the green cone photopigment is abnormal. Yellow and green appear redder and it is difficult to tell violet from blue. This condition is mild and doesn’t interfere with daily living. Deuteranomaly is the most common form of color blindness and is an X-linked disorder affecting 5 percent of males.
Deuteranopia: In males with deuteranopia, there are no working green cone cells. They tend to see reds as brownish-yellow and greens as beige. Deuteranopia is an X-linked disorder that affects about 1 percent of males.
Blue-yellow color blindness
Blue-yellow color blindness is rarer than red-green color blindness. Blue-cone (tritan) photopigments are either missing or have limited function.
Tritanomaly: People with tritanomaly have functionally limited blue cone cells. Blue appears greener and it can be difficult to tell yellow and red from pink. Tritanomaly is extremely rare. It is an autosomal dominant disorder affecting males and females equally.
Tritanopia: People with tritanopia, also known as blue-yellow color blindness, lack blue cone cells. Blue appears green and yellow appears violet or light grey. Tritanopia is an extremely rare autosomal recessive disorder affecting males and females equally.
Complete color blindness
People with complete color blindness (monochromacy) don’t experience color at all and the clearness of their vision (visual acuity) may also be affected.
There are two types of monochromacy:
Cone monochromacy: This rare form of color blindness results from a failure of two of the three cone cell photopigments to work. There is red cone monochromacy, green cone monochromacy, and blue cone monochromacy. People with cone monochromacy have trouble distinguishing colors because the brain needs to compare the signals from different types of cones in order to see color. When only one type of cone works, this comparison isn’t possible. People with blue cone monochromacy, may also have reduced visual acuity, near-sightedness, and uncontrollable eye movements, a condition known as nystagmus. Cone monochromacy is an autosomal recessive disorder.
Rod monochromacy or achromatopsia: This type of monochromacy is rare and is the most severe form of color blindness. It is present at birth. None of the cone cells have functional photopigments. Lacking all cone vision, people with rod monochromacy see the world in black, white, and gray. And since rods respond to dim light, people with rod monochromacy tend to be photophobic – very uncomfortable in bright environments. They also experience nystagmus. Rod monochromacy is an autosomal recessive disorder.
Normal reference ranges can vary depending on the laboratory and the method used for testing. You must use the range supplied by the laboratory that performed your test to evaluate whether your results are "within normal limits."
Additional Materials (19)
What It's Like To Be Color Blind
Video by BuzzFeed Multiplayer/YouTube
Colorblind - A Colorful Guide to Colorblindness (infographic) V1
Video by gleiberkid/YouTube
How Many Colors Can We See?
Video by SciShow/YouTube
This Is What Color Blind People See With These Viral Glasses
Video by Tech Insider/YouTube
Chromosome X&Y (23) - Colour Blindness
Video by The Royal Institution/YouTube
How Vision Tests Work | Living Healthy Chicago
Video by LivingHealthyChicago/YouTube
Colorblindness
An Ishihara test image as seen by subjects with normal color vision and by those with a variety of color deficiencies.
Image by Eddau processed File:Ishihara 2.svg by User:Sakurambo,
Ishihara Plate 9
Ishihara Plate 9
Image by Unknown
Tritanopia color-blind
How tritanopia color-blind people see the world.
Image by Tohaomg
Cone Cells
Illustration of Cone cell structure in the retina
Image by Ivo Kruusamagi
Rod Cells
Illustration of Rod cell structure in the retina
Image by Madhero88
Rod Cells
Cross section of the retina. Rods are visible at far right.
Image by Cajal , Anka Friedrich (talk) , vectorisation by chris
Cone Cells
Seeing red. A. Light from the sun hits the apple. Some wavelengths are blocked by the chemicals in the apple's skin. B. Reflected wavelengths pass through the pupil and excite the cone cells at the back of the eye. C. The cones send a coded message to the brain about the wavelengths entering the eye. In this example, the L-cones are very excited, the M-cones are a little bit excited and the S cones are hardly excited at all. The brain translates this code into a sensation of "red".
Image by Wade A and Benjamin A
Ishihara Plate for testing on Deuteranopia
Ishihara Plate for testing on Deuteranopia. Test for color blindness.
Image by Dan-yell / https://commons.wikimedia.org/wiki/File:Ishihara-Test.svg
Ishihara 3
Ishihara colourblindness test No 3
Image by en:Shinobu Ishihara (died January 3, 1963)/Wikimedia
Ishihara 1
Ishihara Plate No. 1 (Number 12). Used to for the en:Ishihata test of color blindness.
Image by Nicoguaro/Wikimedia
Rough gray and white representation of a test chart so that people with complete color blindness can also get an impression of the test.
Image by Barbarossa at Dutch Wikipedia/Wikimedia
Ishihara 19
Image by /Wikimedia
Red-green colour blindness, do you have it?
Video by Demystifying Medicine/YouTube
2:38
What It's Like To Be Color Blind
BuzzFeed Multiplayer/YouTube
2:47
Colorblind - A Colorful Guide to Colorblindness (infographic) V1
gleiberkid/YouTube
2:35
How Many Colors Can We See?
SciShow/YouTube
3:43
This Is What Color Blind People See With These Viral Glasses
Tech Insider/YouTube
2:23
Chromosome X&Y (23) - Colour Blindness
The Royal Institution/YouTube
3:32
How Vision Tests Work | Living Healthy Chicago
LivingHealthyChicago/YouTube
Colorblindness
Eddau processed File:Ishihara 2.svg by User:Sakurambo,
Ishihara Plate 9
Unknown
Tritanopia color-blind
Tohaomg
Cone Cells
Ivo Kruusamagi
Rod Cells
Madhero88
Rod Cells
Cajal , Anka Friedrich (talk) , vectorisation by chris
en:Shinobu Ishihara (died January 3, 1963)/Wikimedia
Ishihara 1
Nicoguaro/Wikimedia
Rough gray and white representation of a test chart so that people with complete color blindness can also get an impression of the test.
Barbarossa at Dutch Wikipedia/Wikimedia
Ishihara 19
/Wikimedia
6:29
Red-green colour blindness, do you have it?
Demystifying Medicine/YouTube
Vision Screening
Vision Screening
Also called: Pediatric Eye Exam
A vision screening is an eye test that looks for potential vision problems. If a screening shows a potential problem, you will be referred to an eye care specialist for diagnosis and treatment. Many eye disorders are easily treatable when found early.
Vision Screening
Also called: Pediatric Eye Exam
A vision screening is an eye test that looks for potential vision problems. If a screening shows a potential problem, you will be referred to an eye care specialist for diagnosis and treatment. Many eye disorders are easily treatable when found early.
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Use the slider below to see how your results affect your
health.
Your result is Pass.
A pass result means the baby's both eyes follow the target easily and smoothly, indicating adequate development of visual perception.
Related conditions
{"label":"Red reflex reference range","scale":"lin","step":0.25,"hideunits":true,"items":[{"flag":"normal","label":{"short":"Pass","long":"Pass","orientation":"horizontal"},"values":{"min":0,"max":1},"text":"A pass or normal result means that retinal reflexes are equal in symmetry of pattern, color and intensity. A red reflex should appear red, orange, or yellow and be symmetric across both pupils.","conditions":[]},{"flag":"abnormal","label":{"short":"Refer","long":"Refer","orientation":"horizontal"},"values":{"min":1,"max":2},"text":"A refer or abnormal result reveals a reflex that is asymmetric (one eye with a brighter reflex than the other), has dark spots or has an obviously decreased reflex. In the presence of a leukocoria, one or both pupils may appear white instead of the normal red color expected and immediate referral is required.","conditions":["Leukocoria","Retinoblastoma","Cataract","Glaucoma","Retinal detachment","Retinopathy of prematurity","Coloboma","Optic nerve abnormalities","Refractive errors","Aniridia"]}],"value":0.5}[{"normal":0},{"abnormal":0}]
Use the slider below to see how your results affect your
health.
Your result is Pass.
A pass or normal result means that retinal reflexes are equal in symmetry of pattern, color and intensity. A red reflex should appear red, orange, or yellow and be symmetric across both pupils.
Related conditions
{"label":"Visual acuity reference range","scale":"lin","step":0.01,"hideunits":false,"items":[{"flag":"abnormal","label":{"short":"BNB","long":"Blindness\/near blindness","orientation":"vertical"},"values":{"min":0,"max":0.02},"text":"<strong>US: 20\/1000 or less (Metric: 1\/60 or less)<\/strong><br \/>\nIn this range, the person must rely on substitution skills, while the original skills, if any, are unreliable and may at most serve as an adjunct.","conditions":[]},{"flag":"abnormal","label":{"short":"PVI","long":"Profound vision impairment","orientation":"vertical"},"values":{"min":0.02,"max":0.04},"text":"<strong>US: 20\/1000 to 20\/500 (Metric: 2\/60)<\/strong><br \/>\nIn this range, the options for vision enhancement become limited. Reliance gradually shifts from enhancement aids to substitution aids and skills.","conditions":[]},{"flag":"abnormal","label":{"short":"SVI","long":"Severe vision impairment","orientation":"vertical"},"values":{"min":0.04,"max":0.125},"text":"<strong>US: 20\/400 to 20\/200 (Metric: 3\/60 to 6\/60)<\/strong><br \/>\nIn this range performance is below normal and endurance is limited. You may need vision enhancing assistive devices.","conditions":[]},{"flag":"borderline","label":{"short":"MVI","long":"Moderate vision impairment","orientation":"vertical"},"values":{"min":0.125,"max":0.32},"text":"<strong>US: 20\/160 to 20\/80 (Metric: 6\/48 to 6\/24)<\/strong><br \/>\nYou may need corrective lenses (i.e. glasses or contacts) in order to have normal vision. You may also have an eye condition, which requires further testing.","conditions":[]},{"flag":"borderline","label":{"short":"MVI","long":"Mild vision impairment","orientation":"vertical"},"values":{"min":0.32,"max":0.8},"text":"<strong>US: 20\/63 to 20\/32 (Metric: 6\/18 to 6\/10)<\/strong><br \/>\nYou may need corrective lenses (i.e. glasses or contacts) in order to have normal vision. You may also have an eye condition, which requires further testing.","conditions":[]},{"flag":"normal","label":{"short":"NV","long":"Normal vision","orientation":"vertical"},"values":{"min":0.8,"max":1.6},"text":"<strong>US: 20\/25 to 20\/12 (Metric: 6\/7.5 to 6\/4)<\/strong><br \/>\nVisual acuity is expressed as a decimal or a fraction. 1 = US 20\/20 or metric 6\/6 is considered optimal vision. <ul><li>The top number refers to the distance you stand from the chart. This is often 20 feet (6 meters).<\/li><li>The bottom number indicates the distance at which a person with normal eyesight could read the same line you correctly read.<\/li><\/ul>","conditions":[]}],"units":[{"printSymbol":"{ratio}","code":"{ratio}","name":"ratio"}],"value":1.2}[{"abnormal":2},{"abnormal":1},{"abnormal":0},{"borderline":1},{"borderline":0},{"normal":0}]
Use the slider below to see how your results affect your
health.
{ratio}
0.02
0.04
0.125
0.32
0.8
Your result is Normal vision.
US: 20/25 to 20/12 (Metric: 6/7.5 to 6/4)
Visual acuity is expressed as a decimal or a fraction. 1 = US 20/20 or metric 6/6 is considered optimal vision.
The top number refers to the distance you stand from the chart. This is often 20 feet (6 meters).
The bottom number indicates the distance at which a person with normal eyesight could read the same line you correctly read.
Related conditions
{"label":"Color vision reference range","scale":"lin","step":0.25,"hideunits":true,"items":[{"flag":"normal","label":{"short":"N","long":"Normal","orientation":"horizontal"},"values":{"min":0,"max":1},"text":"You should be able to distinguish between all colors.","conditions":[]},{"flag":"borderline","label":{"short":"RGCB","long":"Red-Green Color\u00a0Blindness","orientation":"horizontal"},"values":{"min":1,"max":2},"text":"<p>The most common types of hereditary color blindness are due to the loss or limited function of red cone (known as protan) or green cone (deutran) photopigments. This kind of color blindness is commonly referred to as red-green color blindness.<\/p>","conditions":["Protanomaly","Protanopia","Deuteranomaly","Deuteranopia"]},{"flag":"borderline","label":{"short":"BYCB","long":"Blue-Yellow Color\u00a0Blindness","orientation":"horizontal"},"values":{"min":2,"max":3},"text":"<p>Blue-yellow color blindness is rarer than red-green color blindness. Blue-cone (tritan) photopigments are either missing or have limited function. <\/p>","conditions":["Tritanomaly","Tritanopia"]},{"flag":"borderline","label":{"short":"CCB","long":"Complete color\u00a0blindness","orientation":"horizontal"},"values":{"min":3,"max":4},"text":"<p>People with complete color blindness (monochromacy) don\u2019t experience color at all and the clearness of their vision (visual acuity) may also be affected. <\/p>","conditions":["Cone monochromacy","Rod monochromacy or achromatopsia"]}],"value":0.5}[{"normal":0},{"borderline":0},{"borderline":1},{"borderline":2}]
Use the slider below to see how your results affect your
health.
Your result is Normal.
You should be able to distinguish between all colors.
Related conditions
A vision screening is a brief test that mainly checks how well you can see things up close and far away. It's also called an eye test. The test usually involves reading letters on an eye chart. A vision screening is a quick way to find out if you need a comprehensive (complete) eye exam. A complete exam checks both your vision and eye health. It looks for signs of serious eye disorders that may not have symptoms, such as glaucoma.
Children usually have vision screening tests as part of routine health checkups. Older children may also have vision screening tests at school. For infants and toddlers, health care providers use different screening tests to check the health of the child's eyes and whether the eye muscles are working correctly.
Adults may have their vision screened during routine health checkups. But usually, their vision is screened as part of a complete eye exam from an eye care specialist. Eye care specialists who do complete exams include ophthalmologists and optometrists. Ophthalmologists are medical doctors who diagnose and treat all types of vision and eye disorders. Optometrists have advanced training to diagnose are treat certain types of vision and eye disorders.
Vision screening may miss certain types of eye disorders, so it's important for children and adults to have regular eye exams. Your or your child's provider or eye care specialist can tell you how often to have eye exams.
For infants and children: Your child's provider will use special vision screening tests to look for signs of common eye conditions that need early treatment to prevent long-term loss of vision. These eye conditions include:
Amblyopia. Children with amblyopia have poor vision that usually happens in just one eye. It's caused by a problem with how the brain and eye work together. It's sometimes called "lazy eye." Amblyopia is the most common cause of vision loss in children.
Strabismus. This condition causes each eye to look in a different direction. One or both eyes may turn in ("cross-eyes") or turn out ("walleyes"). If strabismus isn't corrected, it can cause amblyopia and permanent eye damage.
For adults and children starting at about age 3, screening for problems with near and far vision is used to help find common vision problems that can be corrected with eyeglasses or contact lenses. In certain cases, eye surgery may also be an option. These conditions include:
Nearsightedness (myopia), a condition that makes far away things look blurry.
Farsightedness (hyperopia), a condition that makes close-up things look blurry.
Astigmatism, which causes generally blurry vision and makes it hard to see at night.
Presbyopia (only in middle-aged adults and older), this condition makes it hard to see things up close. It's a normal part of aging that makes the lens of the eye less flexible. Presbyopia often begins around age 45.
For adults, vision screening helps find out whether you need a complete eye exam from an eye care specialist. If you have vision screening as part of a complete eye exam, the test will show how well you're seeing at different distances, including with corrective lenses (eyeglasses or contact lenses). If you have problems with your eyes or vision, contact your provider or eye care specialist.
Babies and children need regular vision screening. This helps find and correct vision problems before they affect learning or cause permanent vision loss. Ask your child's provider how often your child should have vision screening tests. In general:
Newborns should be checked for eye infections and signs of other eye disorders.
At 6 months to a year, eyes and vision should be checked during a regular well-baby visit. These tests are needed to check for early signs of strabismus.
At 3 years, screening for near and far vision may begin for children who are able to describe what they see on an eye chart. This screening can be used with other tests to check for signs of amblyopia. All children should have at least one vision screening between age 3 and 5.
If your child has symptoms of an eye disorder, a vision screening may help decide if an exam from an eye care specialist is needed.
For babies under a year old, symptoms include:
After 3 months: Not being able to follow a moving toy or other object with their eyes.
After 4 months: Eyes that don't look properly lined up. Before 4 months, it's normal if your baby's eyes briefly look in different directions from each other.
For older children, other symptoms of vision problems include:
Squinting or frowning
Closing or covering one eye
Trouble reading and/or doing close-up work
Complaining that things are blurry
Blinking more than usual
Crankiness when using close-up vision, such as looking at books
One or both eyes that are watery, red, swollen, or crusted
There are several types of vision screening tests.
Vision screening for children and adults includes:
Distance vision test. This test is also called a "visual acuity" test. It checks how well you can see things far away. Usually, you'll read rows of letters off a wall chart or a video monitor. Each row of letters is smaller than the one before it. To take the test, you usually stand 20 feet from the chart and cover one eye. You read the letters one row at a time until you get to a row with letters that are too small for you to see. Each eye is tested separately. Some eye charts use a capital E that points in different directions. Special charts for young children may use pictures or symbols.
Close-up vision test. For this test, you hold a small card about 14 inches away from your face. The card has several lines of printed text that get smaller and smaller. You read the text out loud using both eyes at the same time. This test checks for farsightedness in children and adults, and for presbyopia in adults.
Color blindness test. Color blindness means you see colors differently than most people. You may also have trouble telling certain colors apart. Children are usually tested once for color vision. They're shown a picture of colored numbers or symbols in a background of multicolored dots. If they can't see the numbers or symbols, they are color blind.
Vision screening for infants includes checking:
How well your baby's eyes can follow a moving object, such as a toy
How your baby's pupils (the black center part of the eye) respond to a bright light
Whether your baby blinks when a light shines in the baby's eye
Whether both eyes focus together
If you or your child wears glasses or contact lenses, bring them with you to the screening. Your provider may want to check the prescription.
There is no risk to a vision screening.
If vision screening shows a possible vision problem or eye disorder, you or your child will likely be referred to an eye care specialist for a more complete eye exam and treatment.
There are different types of eye care specialists. These are some of the most common types:
Ophthalmologists are medical doctors who specialize in preventing, diagnosing, and treating eye disease. They provide complete eye exams, prescribe eyeglasses and contact lenses, and perform eye surgery.
Optometrists are health care professionals who specialize in vision problems and eye disorders. They provide many of the same services as ophthalmologists, including eye exams, prescribing eyeglasses and contact lenses, and treating some eye disorders. In some states, optometrists can perform certain eye surgeries. For complex eye disorders or surgeries, you will need to see an ophthalmologist.
Opticians are health professionals who are trained to fill prescriptions for eyeglasses. They fit you for frames and prepare your eyeglasses. Many opticians also provide contact lenses. An optician can't give you a complete eye exam, but may screen your vision with an eye chart.
Vision Screening: MedlinePlus Medical Test [accessed on Dec 19, 2022]
Additional Materials (33)
Performing a Retinoscopy
An eye care professional performs retinoscopy to determine the child’s refractive error (eyeglass prescription).
Image by National Eye Institute
Eye exam using an occluder
An occluder allows the eye care professional to test a child’s eyes one at a time.
Image by National Eye Institute
Eye Exam for Glasses
An eye care professional tests a child’s eyeglass prescription.
Image by National Eye Institute
Pediatric Eye Exam
An eye care professional conducts a pediatric eye exam on a child.
Image by National Eye Institute
3-D Vision
An eye care professional test a child’s stereoscopic vision (3-D vision).
Image by National Eye Institute
Using a Slit Lamp
A portable slit lamp, with its high magnification, allows the eye care professional to examine the front of the eye of a cooperative child.
Image by National Eye Institute
Using a Slit Lamp
A portable slip lamp, with its high magnification, allows the eye care professional to examine the front of the eye of a cooperative child.
Image by National Eye Institute
Pediatric Eye Exam
An eye care professional performs retinoscopy to determine the child’s refractive error (eyeglass prescription).
Image by National Eye Institute
Pediatric Eye Exam
An eye care professional uses a puppet get a child’s attention during an eye exam.
Image by National Eye Institute
Using an Occluder
An occluder allows the eye care professional to test a patient's eyes one at a time.
Image by National Eye Institute
Child's Eye Exam
Lenses placed in a trial frame help determine eyeglass prescription.
Image by National Eye Institute, National Institutes of Health
Using an Ophthalmoscope
A doctor examines a child's retina with an ophthalmoscope.
Image by National Eye Institute
Eye Care Consultation
An eye care professional consults with a mother about her child’s condition.
Image by National Eye Institute
Pediatric Eye Exam
A portable slit lamp, with its high magnification, allows the eye care professional to examine the front of the eye of a cooperative child.
Image by National Eye Institute
Indirect ophthalmoscope
After the child’s eyes are dilated, an indirect ophthalmoscope provides the eye care professional with a wider view of the retina.
Image by National Eye Institute
Examining for Crossed Eyes
An eye care professional examines a child for crossed eyes (strabismus).
Image by National Eye Institute
Determining Eyeglass Prescription
An eye care professional performs retinoscopy to determine the child’s refractive error (eyeglass prescription).
Image by National Eye Institute
Using an Occluder
An occluder allows the eye care professional to test a patient's eyes one at a time.
Image by National Eye Institute
Viewing the Retina and Optic Nerve
A direct ophthalmoscope allows the eye care professional to examine the retina and optic nerve.
Image by National Eye Institute
Using a Direct Ophthalmoscope
A direct ophthalmoscope allows the eye care professional to examine the retina and optic nerve.
Image by National Eye Institute
Eye Care Consultation
Eye care professional consults with mother about child's condition.
Image by National Eye Institute
Screening for Color Vision Defects
Eye care professional screens child for color vision defects.
Image by National Eye Institute
Screening for Color Vision Defects
Eye care professional screens child for color vision defects.
Image by National Eye Institute
Screening for Color Vision Defects
Eye care professional screens child for color vision defects.
Image by National Eye Institute
Using a Slit Lamp
A slit lamp, with its high magnification, allows the eye care professional to examine the front of the eye.
Image by National Eye Institute
Determining Eyeglass Prescription
An eye care professional determines a patient's eyeglass prescription.
Image by National Eye Institute
Trial Frame and Lens
A patient wears a trial frame and lens.
Image by National Eye Institute
Applying Eye Drops
An eye care professional applies eyedrops to dilate a child’s pupils.
Image by National Eye Institute
Using a Phoropter
An eye care professional uses a phoropter to detect refractive errors in a teenage patient.
Image by National Eye Institute
Do I Need Glasses?
Video by SciShow Kids/YouTube
Visual Acuity Test with Snellen Eye Chart Exam | Cranial Nerve 2 Assessment Nursing
Video by RegisteredNurseRN/YouTube
Ask a Scientist: Nearsighted or Farsighted
Video by National Eye Institute, NIH/YouTube
Binocular Fix and Follow
Document by www.health.state.mn.us
Performing a Retinoscopy
National Eye Institute
Eye exam using an occluder
National Eye Institute
Eye Exam for Glasses
National Eye Institute
Pediatric Eye Exam
National Eye Institute
3-D Vision
National Eye Institute
Using a Slit Lamp
National Eye Institute
Using a Slit Lamp
National Eye Institute
Pediatric Eye Exam
National Eye Institute
Pediatric Eye Exam
National Eye Institute
Using an Occluder
National Eye Institute
Child's Eye Exam
National Eye Institute, National Institutes of Health
Using an Ophthalmoscope
National Eye Institute
Eye Care Consultation
National Eye Institute
Pediatric Eye Exam
National Eye Institute
Indirect ophthalmoscope
National Eye Institute
Examining for Crossed Eyes
National Eye Institute
Determining Eyeglass Prescription
National Eye Institute
Using an Occluder
National Eye Institute
Viewing the Retina and Optic Nerve
National Eye Institute
Using a Direct Ophthalmoscope
National Eye Institute
Eye Care Consultation
National Eye Institute
Screening for Color Vision Defects
National Eye Institute
Screening for Color Vision Defects
National Eye Institute
Screening for Color Vision Defects
National Eye Institute
Using a Slit Lamp
National Eye Institute
Determining Eyeglass Prescription
National Eye Institute
Trial Frame and Lens
National Eye Institute
Applying Eye Drops
National Eye Institute
Using a Phoropter
National Eye Institute
4:36
Do I Need Glasses?
SciShow Kids/YouTube
2:09
Visual Acuity Test with Snellen Eye Chart Exam | Cranial Nerve 2 Assessment Nursing
RegisteredNurseRN/YouTube
2:47
Ask a Scientist: Nearsighted or Farsighted
National Eye Institute, NIH/YouTube
Binocular Fix and Follow
www.health.state.mn.us
Eye Examinations
Eye Examinations
Also called: Eye Exams, Routine Eye Examination, Standard Ophthalmic Exam, Vision Tests
A standard eye exam is a series of tests done to check your vision and the health of your eyes. Key elements of an eye examination include dilation, tonometry, visual field test and a visual acuity test.
Eye Examinations
Also called: Eye Exams, Routine Eye Examination, Standard Ophthalmic Exam, Vision Tests
A standard eye exam is a series of tests done to check your vision and the health of your eyes. Key elements of an eye examination include dilation, tonometry, visual field test and a visual acuity test.
Eye examinations tend to follow a certain pattern: After talking with your doctor about the type and severity of your symptoms, both eyes will usually be tested to measure the visual acuity (sharpness of sight). Then the doctor will look at your eyes from the outside, take a closer look at them using a slit lamp, and measure the intraocular pressure (the pressure inside the eyeball). Eye drops are given before some tests to dilate (enlarge) the pupil of the eye for a certain amount of time. This makes it easier for the doctor to see the back of the eye. Depending on the symptoms and any other medical conditions you may have, the eye examination might be carried out differently and additional tests might be done.
Structure of the eye
Eye examinations may be necessary for various reasons, for instance due to external eye injuries or sudden vision problems. Vision also tends to get worse with age, so many people end up going to see an eye doctor at some point.
General eye examinations typically involve testing your vision and your pupillary response (how your pupils react). Pupils usually automatically contract and get smaller when light enters the eye.
The doctor first looks at the eye from the outside to see whether, for instance, the conjunctiva or eyelids are red and inflamed. The conjunctiva are the membranes lining the exposed part of the eyeball and inner surface of the eyelids. If your eye hurts, it is important to describe exactly where it hurts – e.g. on the surface of the eye, inside the eye or only when you move your eye? Eye pain can also radiate to your forehead or temples.
If you aren't sure whether your vision has got worse, you can have your visual acuity (sharpness of sight) tested by an eyespecialist. To do this eye test, one of your eyes is covered and you are asked to look at an eye chart with your other eye. The chart may have letters, numbers or C-shapes on it. These get smaller as you go down the chart.
Your visual acuity is measured by determining which of the figures you can still recognize from five meters away. The eye doctor will also check your near vision by holding a card with a similar chart on it at reading distance (about 30 centimeters). If necessary, this eye test can then be repeated using corrective lenses. Technically speaking, visual acuity is a measure of how well you can see two points as being separate. The closer together the points are, the more difficult this becomes.
Vision is often assessed using other tests too. These include color vision tests, where you are asked to identify certain patterns in multicolored pictures. Eye movement and the position of your eyes relative to one another are important too. In children who have a squint, for example, the relative position of their eyes is abnormal due to different abilities of their left and right eye to see clearly. Tests to check your field of vision are also common.
Your field of vision (or visual field) is what you can see without moving your eye. The test is done using a bowl-shaped instrument known as a perimeter. With your head supported by a chin rest, you focus on a fixed spot at the center of the bowl. Lights flash in the bowl, and may move around or become increasingly brighter. If you see a flash or notice a change, you press a button. The more areas in your field of vision are tested, the more accurate the diagnosis – but the test will then take longer as a result.
Perimetry test: Press a button everytime you see a flash
Your field of vision is very important as it helps you know what is around you. Because various medical conditions affect the field of vision, perimetry tests are often done if damage to the retina or optic nerve is suspected, or if someone has headaches or dizzinessfor no known reason. Eye diseases like glaucoma and age-related macular degeneration also lead to changes in the field of vision. Although perimetry tests aren't painful, they can be quite tiring because you have to concentrate for a long time.
A slit lamp is a microscope that projects a narrow, slit-shaped light. It is one of the main instruments used by eye specialists. You are asked to place your head on a chin rest. The doctor sits across from you and shines the light into your eyes, one at a time.
The intense line of light and various lighting options (direct, indirect, diffuse) enable the doctor to see most of the different areas of the eye magnified up to 60 times: the front, middle and back of the eye, and even as far back as the retina in the fundus of the eye. Modern slit lamps also include a device that measures intraocular pressure (the pressure inside the eyeball).
A special device known as an ophthalmoscope can be used to look at the fundus (back) of the eye through the pupil and examine structures like the retina, optic nerve, blood vessels and the choroid coat. This examination is known as ophthalmoscopy or funduscopy ("fundus" is the Latin word for "bottom" or "base"). About 20 minutes before the examination, the pupils of the eyes are dilated (enlarged) using eye drops.
In the direct exam, the doctor positions the ophthalmoscope close to the eye and shines a beam of light directly into it to see a small magnified section of the back of the eye. This is particularly useful for examining the structures at the center of the eye's fundus, including the optic nerve, the blood vessels and the macula.
In the indirect exam, the doctor uses a condensing lens with a bright light to examine the eye from a distance of about 60 centimeters. This allows them to see a larger area of the fundus, providing a better overview as well as a three-dimensional image. A slit lamp is sometimes used at the same time. Doing so greatly magnifies the retina and provides better lighting.
Conditions such as retinal detachment and optic nerve damage can be diagnosed using ophthalmoscopy. This examination can also be a good idea in people who have diabetes or high blood pressure because both of these conditions can damage blood vessels in the eye.
If your pupils are dilated using eye drops, your eyes become very sensitive to light and your vision becomes blurred. For this reason, you are only allowed to drive a car or operate machinery again once the effect of the eye drops has worn off.
The measurement of intraocular pressure (tonometry) is one of the most common eye examinations. The pressure inside the eyeball becomes too high if a fluid produced in the eye (called aqueous humor) cannot drain properly and starts to build up. An intraocular pressure of between 10 and 21 mmHg (millimeters of mercury) is considered to be normal in adults.
Various instruments can be used to measure the pressure in the eye. In what is known as applanation tonometry, the cornea is first numbed using eye drops. Then a small measuring device is placed against the surface of the cornea, putting a little pressure on the eye.
The device measures how much pressure is needed to flatten the cornea by 3 millimeters. This is a measure of the pressure inside the eye.
Intraocular pressure can also be measured using an approach known as non-contact tonometry. Here the pressure is measured by applying a short puff of air to the cornea. Neither of these examinations are painful.
Other eye examinations can be done to confirm certain diagnoses and help plan treatment. For instance, the retina can be examined using fluorescein angiography. This involves injecting a fluorescent dye into a vein in the arm. The dye spreads through all the blood vessels in the body, including those in the retina. The doctor can then use a special camera to detect changes in the blood vessels of the eye.
Optical coherence tomography (OCT) is another type of eye examination. OCT uses a laser to measure things like the thickness of the retina. This technique can be applied to detect the build-up of fluid in the retina.
Standard eye exam: MedlinePlus Medical Encyclopedia [accessed on Sep 03, 2018]
Additional Materials (41)
Sclera (White of the Eye)
Human eye revealing sclera
Image by agnesliinnea
Slit Lamp Photo of Eye
Slit Lamp Photo of Eye
Image by U.S. Air Force photo by Senior Airman Zachary Hada/Released
Tuberous Sclerosis - What is the prognosis?
The prognosis for individuals with TSC is highly variable and depends on the severity of symptoms. Those individuals with mild symptoms usually do well and have a normal life expectancy, while paying attention to TSC-specific issues. Individuals who are severely affected can suffer from severe mental retardation and persistent epilepsy.
Image by National Eye Institute of the NIH
Eye diagram — side view
Image by National Eye Institute (NEI)
Pupil Response
Dilated and Undilated Pupil - Portions of the retina that can be seen through an undilated versus a dilated pupil.
Image by National Eye Institute, National Institutes of Health
Low Vision
What is Low Vision Infographic. Information on low vision: causes, numbers, what we can do, and vision rehabilitation.
Image by National Eye Institute
Human Eye
Anatomy of the human eye with corneal cross-section
Image by National Eye Institute
Dilated Pupil
My friend had a scratch down her eye and had to have it dilated at hospital for three days with drops.
Image by Sophie Riches
Eye Drops
Eye drops ophthalmology service Hospital Douala Cameroun
Image by Happi Raphael/Wikimedia
Retinography
Self made ophtalmogram of the retina of the right eye. It shows the optic disc as a bright area on the right (nasal side) where blood vessels converge. The spot to the left (temporal side) of the centre is the macula. The grey, more diffuse spot in the centre is a shadow artifact.
Image by Ske.
Age-Related Macular Degeneration Overview
Macular Degeneration Projected Statistics
Image by National Eye Institute
Sensitive content
This media may include sensitive content
Eye exam
Capt. Luanne Danes uses a light to check the anterior segment of Master Sgt. Timothy Vanderhoff's eye during his visit to the Optometry Clinic Nov. 19, 2009, Eielson Air Force Base, Alaska. Captain Danes is looking for healthy structure of the eye and ensuring no corneal disease is present. Captain Danes, officer in charge of Optometry, is assigned to the 354th Medical Operation Squadron. Sergeant Vanderhoff, crew chief, is assigned to the 168th Aircraft Maintenance Squadron. (U.S. Air Force photo/Staff Sgt. Christopher Boitz)
Image by U.S. Air Force photo/Staff Sgt. Christopher Boitz
Eye exam
U.S. Navy Lt. Patricia Salazar examines a patient's eyes at a Continuing Promise medical clinic set up by staff assigned to the hospital ship USNS Comfort in Paita, Peru
Image by Petty Officer 1st Class Brian A. Goyak, U.S. Navy
Eye Examination
Eye Examination
Image by 12019
Infant Eye cross section
Cross-section of the healthy eye of an infant, showing a retina that is in perfect condition, having never been exposed to smoke-borne toxins that would compromise circulation and result in retinal damage. Image supports content showing the health benefits of smoke cessation.
Image by TheVisualMD
Cornea
Cornea - transparent covering over the eye
Image by www.keratomania.com Eye diagram by Chabacano via Wikimedia Commons
anatomy of the human eye, iris, cornea, pupil
Image by skeeze
Animation: Dilated Eye Exam
Video by National Eye Institute, NIH/YouTube
Iris (anatomy)
Image by Shanon
Pupil
Dilated and Undilated Pupil - Portions of the retina that can be seen through an undilated versus a dilated pupil.
Image by National Eye Institute, National Institutes of Health
How is glaucoma detected?
The PASCAL Dynamic Contour Tonometer
Image by Tonywirthlin at English Wikipedia
Optical Coherence Tomography
A detailed cross-sectional image of the back of the eye is obtained using an optical coherence tomography (OCT).
Image by National Eye Institute, National Institutes of Health
Help protect yourself from getting and spreading Pink Eye (conjunctivitis)
Help protect yourself from getting and spreading Pink Eye (conjunctivitis)
Image by CDC
Dry Eye
Diffuse lissamine green staining in a person with severe dry eye.
Image by Jesse Vislisel, MD and Brice Critser, CRA
Tear Production
Cornea - Structures involved in tear production.
Image by National Eye Institute
Eyeglasses on display
Eyeglasses are displayed at the optometry clinic March 11, 2016, at Malmstrom Air Force Base, Mont. The clinic hosts an internship program open to students including primary care, ocular disease and two specialty clinics, lasting two months each. (U.S. Air Force photo/Senior Airman Jaeda Tookes)
Image by U.S. Air Force photo/Senior Airman Jaeda Tookes
Extrinsic Eye Muscles
Extrinsic Eye Muscles
Image by OpenStax
Eye movements elevators
Eye movements elevators
Image by Patrick J. Lynch, medical illustrator; C. Carl Jaffe, MD, cardiologist
Treating Amblyopia
In addition to patching the eye, one hour of “near” work, or close-up work, such as coloring, is part of the treatment for amblyopia.
Image by National Eye Institute, National Institutes of Health
Sensitive content
This media may include sensitive content
Routine eye exam, rare diagnosis
This image shows deposits of cholesterol on the back of an eye affected by Coats’ Disease. The rare, congenital disease, only found in about one in 100,000 people, is caused by abnormal blood vessel development behind the retina. The affected blood vessels leak blood content into the eye leading to partial or complete retinal detachment if not treated. (Courtesy photo)
Image by Courtesy photo
Checking an elderly patient's eyes
U.S. Air Force Capt. Eric Noll, an optometrist with the 354th Medical Group, Eielson Air Force Base, Alaska, checks a patient’s eyesight at Tata Primary and Secondary School during Pacific Angel 18-3 in Luganville, Espiritu Santo Island, Vanuatu, July 16, 2018. The optometry team handed out 228 pairs of eye glasses and 534 pairs of sunglasses during the first two days of the clinic. Now entering its eleventh year Operation PAC ANGEL ensures that the region’s militaries are prepared to work together to address humanitarian crises. (U.S. Air Force photo by Senior Airman Kelsey Tucker)
Image by U.S. Air Force photo by Senior Airman Kelsey Tucker
Eye Exam
U.S. Air Force Maj. Brett Ringger, an optometrist from the Texas Air National Guard’s 136th Airlift Wing, tests a patient’s vision at a health-care clinic being operated by the Air National Guard and U.S. Navy Reserve at Lee County High School in Beattyville, Ky., June 23, 2018. The clinic is one of four that comprised Operation Bobcat, a 10-day mission to provide military medical troops with crucial training in field operations and logistics while offering no-cost health care to the residents of Eastern Kentucky. The clinics, which operated from June 15-24, offered non-emergent medical care; sports physicals; dental cleanings, fillings and extractions; eye exams and no-cost prescription eye glasses. (U.S. Air National Guard photo by Lt. Col. Dale Greer)
U.S. Air Force Maj. Brett Ringger, an optometrist from the Texas Air National Guard’s 136th Airlift Wing, tests a patient’s vision at a health-care clinic being operated by the Air National Guard and U.S. Navy Reserve at Lee County High School in Beattyville, Ky., June 23, 2018. The clinic is one of four that comprised Operation Bobcat, a 10-day mission to provide military medical troops with crucial training in field operations and logistics while offering no-cost health care to the residents of Eastern Kentucky. The clinics, which operated from June 15-24, offered non-emergent medical care; sports physicals; dental cleanings, fillings and extractions; eye exams and no-cost prescription eye glasses. (U.S. Air National Guard photo by Lt. Col. Dale Greer)
Image by U.S. Air National Guard photo by Lt. Col. Dale Greer
Vision Exam
U.S. Air Force Maj. Robert Groves, an optometrist from the New Hampshire Air National Guard’s 157th Air Refueling Wing, conducts a vision exam at a health-care clinic being operated by the Air Guard and U.S. Navy Reserve at Estill County High School in Irvine, Ky., June 21, 2018. The clinic is one of four that comprised Operation Bobcat, a 10-day mission to provide military medical troops with crucial training in field operations and logistics while offering no-cost health care to the residents of Eastern Kentucky. The clinics, which operated from June 15-24, offered non-emergent medical care; sports physicals; dental cleanings, fillings and extractions; eye exams and no-cost prescription eye glasses. (U.S. Air National Guard photo by Lt. Col. Dale Greer)
Image by U.S. Air National Guard photo by Lt. Col. Dale Greer
Eyeglasses selection
U.S. Air Force Master Sgt. Julie Brown (left), a medic from the Texas Air National Guard’s 136th Airlift Wing, helps Lindsey Howard of Richmond, Ky., select frames for a new pair of eyeglasses at a health-care clinic being operated by the Air Guard and U.S. Navy Reserve at Estill County High School in Irvine, Ky., June 21, 2018. The clinic is one of four that comprised Operation Bobcat, a 10-day mission to provide military medical troops with crucial training in field operations and logistics while offering no-cost health care to the residents of Eastern Kentucky. The clinics, which operated from June 15-24, offered non-emergent medical care; sports physicals; dental cleanings, fillings and extractions; eye exams and no-cost prescription eye glasses. (U.S. Air National Guard photo by Lt. Col. Dale Greer)
Image by U.S. Air National Guard photo by Lt. Col. Dale Greer
Eye Exam
U.S. Air Force Maj. Robert Groves, an optometrist from the New Hampshire Air National Guard’s 157th Air Refueling Wing, examines a patient’s eyes at a health-care clinic being operated by the Air Guard and U.S. Navy Reserve at Estill County High School in Irvine, Ky., June 21, 2018. The clinic is one of four that comprised Operation Bobcat, a 10-day mission to provide military medical troops with crucial training in field operations and logistics while offering no-cost health care to the residents of Eastern Kentucky. The clinics, which operated from June 15-24, offered non-emergent medical care; sports physicals; dental cleanings, fillings and extractions; eye exams and no-cost prescription eye glasses. (U.S. Air National Guard photo by Lt. Col. Dale Greer)
Image by U.S. Air National Guard photo by Lt. Col. Dale Greer
Optometry
U.S. Air Force Senior Airman Dane Mendelsohn, a medic from the Kentucky Air National Guard’s 123rd Airlift Wing, screens an optometry patient at a health-care clinic being operated by the Air Guard and U.S. Navy Reserve at Breathitt County High School in Jackson, Ky., June 20, 2018. The Jackson clinic is one of four that comprised Operation Bobcat, a 10-day mission to provide military medical troops with crucial training in field operations and logistics while offering no-cost health care to the residents of Eastern Kentucky. The clinics, which operated from June 15-24, offered non-emergent medical care; sports physicals; dental cleanings, fillings and extractions; eye exams and no-cost prescription eye glasses. (U.S. Air National Guard photo by Lt. Col. Dale Greer)
Image by U.S. Air National Guard photo by Lt. Col. Dale Greer
Visual Test
Visual Test - Comprehensive Eye exam
Image by Paul Diaconu
Slit Lamp test
Slit Lamp test - Comprehensive Eye exam
Image by Paul Diaconu
Presbyopia
Presbyopia - Visual Test
Image by Tumisu
Eye Exam
Eye Exam
Image by David Mark
Sclera (White of the Eye)
agnesliinnea
Slit Lamp Photo of Eye
U.S. Air Force photo by Senior Airman Zachary Hada/Released
Tuberous Sclerosis - What is the prognosis?
National Eye Institute of the NIH
Eye diagram — side view
National Eye Institute (NEI)
Pupil Response
National Eye Institute, National Institutes of Health
Low Vision
National Eye Institute
Human Eye
National Eye Institute
Dilated Pupil
Sophie Riches
Eye Drops
Happi Raphael/Wikimedia
Retinography
Ske.
Age-Related Macular Degeneration Overview
National Eye Institute
Sensitive content
This media may include sensitive content
Eye exam
U.S. Air Force photo/Staff Sgt. Christopher Boitz
Eye exam
Petty Officer 1st Class Brian A. Goyak, U.S. Navy
Eye Examination
12019
Infant Eye cross section
TheVisualMD
Cornea
www.keratomania.com Eye diagram by Chabacano via Wikimedia Commons
anatomy of the human eye, iris, cornea, pupil
skeeze
3:24
Animation: Dilated Eye Exam
National Eye Institute, NIH/YouTube
Iris (anatomy)
Shanon
Pupil
National Eye Institute, National Institutes of Health
How is glaucoma detected?
Tonywirthlin at English Wikipedia
Optical Coherence Tomography
National Eye Institute, National Institutes of Health
Help protect yourself from getting and spreading Pink Eye (conjunctivitis)
CDC
Dry Eye
Jesse Vislisel, MD and Brice Critser, CRA
Tear Production
National Eye Institute
Eyeglasses on display
U.S. Air Force photo/Senior Airman Jaeda Tookes
Extrinsic Eye Muscles
OpenStax
Eye movements elevators
Patrick J. Lynch, medical illustrator; C. Carl Jaffe, MD, cardiologist
Treating Amblyopia
National Eye Institute, National Institutes of Health
Sensitive content
This media may include sensitive content
Routine eye exam, rare diagnosis
Courtesy photo
Checking an elderly patient's eyes
U.S. Air Force photo by Senior Airman Kelsey Tucker
U.S. Air National Guard photo by Lt. Col. Dale Greer
Vision Exam
U.S. Air National Guard photo by Lt. Col. Dale Greer
Eyeglasses selection
U.S. Air National Guard photo by Lt. Col. Dale Greer
Eye Exam
U.S. Air National Guard photo by Lt. Col. Dale Greer
Optometry
U.S. Air National Guard photo by Lt. Col. Dale Greer
Visual Test
Paul Diaconu
Slit Lamp test
Paul Diaconu
Presbyopia
Tumisu
Eye Exam
David Mark
Visual Acuity Test
Visual Acuity Test
Also called: Snellen Test
A visual acuity test is an eye exam that checks the smallest letters you can read on a standardized chart (Snellen chart) or a card held 20 feet (6 meters) away. Visual acuity refers to your ability to recognize the shapes and details of the things you see.
Visual Acuity Test
Also called: Snellen Test
A visual acuity test is an eye exam that checks the smallest letters you can read on a standardized chart (Snellen chart) or a card held 20 feet (6 meters) away. Visual acuity refers to your ability to recognize the shapes and details of the things you see.
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Use the slider below to see how your results affect your
health.
0.02
0.04
0.125
0.32
0.8
Your result is Normal Vision.
US: 20/25 to 20/12 (Metric: 6/7.5 to 6/4)
Visual acuity is expressed as a decimal or a fraction. 1 = US 20/20 or metric 6/6 is considered optimal vision.
The top number refers to the distance you stand from the chart. This is often 20 feet (6 meters).
The bottom number indicates the distance at which a person with normal eyesight could read the same line you correctly read.
Related conditions
If you aren't sure whether your vision has got worse, you can have your visual acuity (sharpness of sight) tested by an eye specialist. To do this eye test, one of your eyes is covered and you are asked to look at an eye chart with your other eye. The chart may have letters, numbers or C-shapes on it. These get smaller as you go down the chart.
Your visual acuity is measured by determining which of the figures you can still recognize from five meters away. The eye doctor will also check your near vision by holding a card with a similar chart on it at reading distance (about 30 centimeters).
If necessary, this eye test can then be repeated using corrective lenses. Technically speaking, visual acuity is a measure of how well you can see two points as being separate. The closer together the points are, the more difficult this becomes.
https://www.ncbi.nlm.nih.gov/pubmedhealth/PMHT0027947/ [accessed on Sep 04, 2018]
Visual acuity test: MedlinePlus Medical Encyclopedia [accessed on Sep 04, 2018]
http://www.icoph.org/downloads/visualstandardsreport.pdf [accessed on Sep 04, 2018]
Visual acuity - Wikipedia [accessed on Sep 04, 2018]
Visual Acuity: What is 20/20 Vision? [accessed on Sep 04, 2018]
https://www.nist.gov/sites/default/files/documents/el/isd/ks/Visual_Acuity_Standards_1.pdf [accessed on Sep 04, 2018]
Normal reference ranges can vary depending on the laboratory and the method used for testing. You must use the range supplied by the laboratory that performed your test to evaluate whether your results are "within normal limits."
Additional Materials (24)
Snellen Eye Chart vs Prescription Glasses
Getting things in focus.
Image by David Travis/Unsplash
The Snellen Chart
The Snellen chart for visual acuity presents a limited number of Roman letters in lines of decreasing size. The line with letters that subtend 5 minutes of an arc from 20 feet represents the smallest letters that a person with normal acuity should be able to read at that distance. The different sizes of letters in the other lines represent rough approximations of what a person of normal acuity can read at different distances. For example, the line that represents 20/200 vision would have larger letters so that they are legible to the person with normal acuity at 200 feet.
Image by CNX Openstax
Saccadic Eye Movements
Saccades are rapid, conjugate movements of the eyes to survey a complicated visual stimulus, or to follow a moving visual stimulus. This image represents the shifts in gaze typical of a person studying a face. Notice the concentration of gaze on the major features of the face and the large number of paths traced between the eyes or around the mouth.
Image by CNX Openstax
Pituitary Tumor
The pituitary gland is located in the sella turcica of the sphenoid bone within the cranial floor, placing it immediately inferior to the optic chiasm. If the pituitary gland develops a tumor, it can press against the fibers crossing in the chiasm. Those fibers are conveying peripheral visual information to the opposite side of the brain, so the patient will experience “tunnel vision”—meaning that only the central visual field will be perceived.
Image by CNX Openstax
Vestibulo-ocular Reflex
If the head is turned in one direction, the coordination of that movement with the fixation of the eyes on a visual stimulus involves a circuit that ties the vestibular sense with the eye movement nuclei through the MLF.
Image by CNX Openstax
Muscles Controlled by the Accessory Nerve
The accessory nerve innervates the sternocleidomastoid and trapezius muscles, both of which attach to the head and to the trunk and shoulders. They can act as antagonists in head flexion and extension, and as synergists in lateral flexion toward the shoulder.
Image by CNX Openstax
Human Eye
Detailed Illustration of the cross section of the Human Eye - 1:posterior segment of eyeball 2:ora serrata 3:ciliary muscle 4:ciliary zonules 5:canal of Schlemm 6:pupil 7:anterior chamber 8:cornea 9:iris 10:lens cortex 11:lens nucleus 12:ciliary process 13:conjunctiva 14:inferior oblique muscle 15:inferior rectus muscle 16:medial rectus muscle 17:retinal arteries and veins 18:optic disc19:dura mater 20:central retinal artery 21:central retinal vein 22:optic nerve 23:vorticose vein 24:bulbar sheath 25:macula 26:fovea 27:sclera 28:choroid 29:superior rectus muscle 30:retina
Image by Chabacano
Dilated fundus examination
Diagram of the Eye Before and After Dilated Eye Exam
Image by National Eye Institute (NEI), National Institutes of Health (NIH)
Macular
Cross-sectional view in grayscale of right human eye
Image by National Eye Institute, National Institutes of Health
What is Presbyopia?
Image by National Eye Institute, NIH
Age Related Macular degeneration - What are some low vision devices?
A scene as it might be viewed by a person with age-related macular degeneration.
Image by National Eye Institute, National Institutes of Health
The Visual System: How Your Eyes Work
Video by National Eye Institute, NIH/YouTube
Your Baby - Visual Development - Birth to One Month
Video by movementlesson/YouTube
Bionic Eye Cures Blindness
Video by Seeker/YouTube
Vision Simulation
Video by Light12434/YouTube
What is Vision Impairment? - Vision Awareness Training Part One
Video by ouhnhs/YouTube
Low Vision
Video by EyeSmart — American Academy of Ophthalmology/YouTube
Structure and working of Human Eye
Video by Enliveeducation/YouTube
Visual Acuity Test with Snellen Eye Chart Exam | Cranial Nerve 2 Assessment Nursing
Video by RegisteredNurseRN/YouTube
How to Check Your Patient's Visual Acuity
Video by dkcalgary/YouTube
Visual Acuity in 5 min
Video by Nick Smith/YouTube
Testing Your Visual Acuity
Video by University of Rochester/YouTube
Part 2: Visual Acuity Exam
Video by ALiEM Educational Videos/YouTube
Visual Acuity - OPHTHALMOLOGY - Ep 4
Video by UBC Medicine - Educational Media/YouTube
Snellen Eye Chart vs Prescription Glasses
David Travis/Unsplash
The Snellen Chart
CNX Openstax
Saccadic Eye Movements
CNX Openstax
Pituitary Tumor
CNX Openstax
Vestibulo-ocular Reflex
CNX Openstax
Muscles Controlled by the Accessory Nerve
CNX Openstax
Human Eye
Chabacano
Dilated fundus examination
National Eye Institute (NEI), National Institutes of Health (NIH)
Macular
National Eye Institute, National Institutes of Health
What is Presbyopia?
National Eye Institute, NIH
Age Related Macular degeneration - What are some low vision devices?
National Eye Institute, National Institutes of Health
2:20
The Visual System: How Your Eyes Work
National Eye Institute, NIH/YouTube
5:40
Your Baby - Visual Development - Birth to One Month
movementlesson/YouTube
3:13
Bionic Eye Cures Blindness
Seeker/YouTube
2:04
Vision Simulation
Light12434/YouTube
11:26
What is Vision Impairment? - Vision Awareness Training Part One
ouhnhs/YouTube
4:11
Low Vision
EyeSmart — American Academy of Ophthalmology/YouTube
5:16
Structure and working of Human Eye
Enliveeducation/YouTube
2:09
Visual Acuity Test with Snellen Eye Chart Exam | Cranial Nerve 2 Assessment Nursing
RegisteredNurseRN/YouTube
12:25
How to Check Your Patient's Visual Acuity
dkcalgary/YouTube
4:58
Visual Acuity in 5 min
Nick Smith/YouTube
2:17
Testing Your Visual Acuity
University of Rochester/YouTube
2:53
Part 2: Visual Acuity Exam
ALiEM Educational Videos/YouTube
2:14
Visual Acuity - OPHTHALMOLOGY - Ep 4
UBC Medicine - Educational Media/YouTube
Visual Field Test
Visual Field Test
Also called: Perimetry, Tangent screen exam, Automated perimetry exam, Goldmann visual field exam, Humphrey visual field exam
A visual field test is an eye examination that can detect dysfunction in central and peripheral vision which may be caused by various medical conditions such as glaucoma, stroke, pituitary disease, brain tumors or other neurological deficits.
Visual Field Test
Also called: Perimetry, Tangent screen exam, Automated perimetry exam, Goldmann visual field exam, Humphrey visual field exam
A visual field test is an eye examination that can detect dysfunction in central and peripheral vision which may be caused by various medical conditions such as glaucoma, stroke, pituitary disease, brain tumors or other neurological deficits.
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Use the slider below to see how your results affect your
health.
Your result is Normal.
The peripheral vision is normal.
Related conditions
Your field of vision (or visual field) is what you can see without moving your eye. The test is done using a bowl-shaped instrument known as a perimeter. With your head supported by a chin rest, you focus on a fixed spot at the center of the bowl. Lights flash in the bowl, and may move around or become increasingly brighter. If you see a flash or notice a change, you press a button. The more areas in your field of vision are tested, the more accurate the diagnosis – but the test will then take longer as a result.
Your field of vision is very important as it helps you know what is around you. Because various medical conditions affect the field of vision, perimetry tests are often done if damage to the retina or optic nerve is suspected, or if someone has headaches or dizziness for no known reason. Eye diseases like glaucoma and age-related macular degeneration also lead to changes in the field of vision. Although perimetry tests aren't painful, they can be quite tiring because you have to concentrate for a long time.
Visual field: MedlinePlus Medical Encyclopedia [accessed on Oct 03, 2018]
Visual field test - Wikipedia [accessed on Oct 03, 2018]
Visual Field Testing for Glaucoma and Other Eye Problems [accessed on Oct 03, 2018]
Normal reference ranges can vary depending on the laboratory and the method used for testing. You must use the range supplied by the laboratory that performed your test to evaluate whether your results are "within normal limits."
Additional Materials (28)
Macular degeneration - Charles Bonnet syndrome (Visual Hallucinations)
This image shows an eye fundus viewed through a retinal camera, with signs of macular degeneration
Image by Tmhlee
Advanced age-related macular degeneration with fibrosis
Advanced age-related macular degeneration with fibrosis.
Image by National Eye Institute, National Institutes of Health
Retinal Disparity
Because of the interocular distance, which results in objects of different distances falling on different spots of the two retinae, the brain can extract depth perception from the two-dimensional information of the visual field.
Image by CNX Openstax
Advanced age-related macular degeneration
A fundus photo showing advanced age-related macular degeneration.
Image by National Eye Institute, National Institutes of Health
Age-Related Macular Degeneration Overview
A fundus photo showing.
Image by National Eye Institute, National Institutes of Health
Perimetry, a visual field test
Image by Institute for Quality and Efficiency in Health Care (IQWiG)
Age-Related Macular Degeneration Overview
A medical illustration depicting macular degeneration.
Image by BruceBlaus
Age-Related Macular Degeneration Overview
Macular Degeneration Projected Statistics
Image by National Eye Institute
Age-Related Macular Degeneration Overview
Age-Related Macular Degeneration information at-a-glance.
Image by NEHEP
Age-Related Macular Degeneration Overview
Macular Degeneration
Image by Ralf Roletschek
Human Head Showing Visual Pathway
3D visualization of the visual pathway based on scanned human data. Electrical nerve impulses travel from the eyes to the occipital lobe in the back of the brain via millions of nerves that make up the \"visual pathway.\" The white matter of the brain is made up of millions of nerve extensions (axons) which connect nerve fibers to other nerve fibers, target tissues or organs. In this illustration, bundles of axons in the white matter (colored blue and red) are seen radiating from the eyes to the visual centers of the brain.
Image by TheVisualMD
Topographic Mapping of the Retina onto the Visual Cortex
The visual field projects onto the retina through the lenses and falls on the retinae as an inverted, reversed image. The topography of this image is maintained as the visual information travels through the visual pathway to the cortex.
Image by CNX Openstax
Ventral and Dorsal Visual Streams
From the primary visual cortex in the occipital lobe, visual processing continues in two streams—one into the temporal lobe and one into the parietal lobe.
Image by CNX Openstax
Brain Revealing Visual Pathway
3D visualization reconstructed from scanned human data of a superior view of the brain revealing the visual pathway and superior sagittal sinus. Electrical nerve impulses travel from the eyes to the occipital lobe in the back of the brain via millions of nerves fibers that make up the \"visual pathway\".
Image by TheVisualMD
The optic disc, optic cup, and macula of a healthy 24 year old female (healthy rim tissue with a deep cup).
The optic disc, optic cup, and macula of a healthy 24 year old female (healthy rim tissue with a deep cup).
Image by Eric Wiessner
Sensitive content
This media may include sensitive content
Muscle and Nerve of Human Eye
3D visualization of the nerves associated with the human eye. Several different nerve types serve the special functions of the structures associated with sight. The optic nerves are paired bundles of fibers that send visual signals from the retina to the brain. The oculomotor, trochlear and abducent nerves control voluntary movements of the eye muscles and eyelids in addition to controlling pupil dilation and lens focusing.
Image by TheVisualMD
Macula of Retina
Instead of getting those crazy eye drops to dilate your eyes so the doctor can look at your retina, they just take a high-resolution digital picture. Much faster and easier. And they keep them on record so they can compare photos from year to year and better diagnose potential problems. The bright spot in the middle is the optic nerve (the blind spot); the darker spot next to the optic nerve is the macula, a small crater in the retina with a higher density of rods and cones, making it the best seeing portion of the eye.
Image by derivative work: Chmee2 (talk) Left_Retina.jpg: Hey Paul
Retina
This image schematically represents optic pathways from each of the 4 quadrants of view for both eyes simultaneously.
Image by Original uploader was Ratznium at en.wikipedia
Vestibulo-ocular Reflex
Connections between the vestibular system and the cranial nerves controlling eye movement keep the eyes centered on a visual stimulus, even though the head is moving. During head movement, the eye muscles move the eyes in the opposite direction as the head movement, keeping the visual stimulus centered in the field of view.
Image by CNX Openstax
Optic Nerve - A bundle of more than 1 million nerve fibers that carries visual messages from the retina to the brain.
Optic Nerve - A bundle of more than 1 million nerve fibers that carries visual messages from the retina to the brain.
Image by TheVisualMD
Partially Sectioned Human Eye Exposing front and back of the eye including the Retina
Three-dimensional visualization reconstructed from human data. Anteriolateral view of a partially sectioned eye, as well as associated eye muscles. As well as being protected by the bony orbital cavity of the skull, the eyeball is anchored in place by several thin strap muscles that attach to virtually every one of its sides except the front. These muscles tug in concert, allowing the eye to move in any direction to track objects. The clear cornea covers and protects the front exterior of the eye while the colored iris dilates and constricts to insure the proper amount of light is striking the back of the eye. The lens contorts to focus the incoming light back to the retina, which covers roughly the entire back half of the eye. Special cells embedded within the retina are responsible for the sensation of light: the cones, for color perception, and rods, for black and white perception. Electrical nerve impulses are channeled into the optic nerve at the back of the eye to the visual cortex in the brain.
Image by TheVisualMD
Human Eye
Detailed Illustration of the Anatomy of the Human Eye
Image by A Hoofring ncbi/nlm/nih
Vestibulo-ocular Reflex
If the head is turned in one direction, the coordination of that movement with the fixation of the eyes on a visual stimulus involves a circuit that ties the vestibular sense with the eye movement nuclei through the MLF.
Image by CNX Openstax
Visual Neural Pathways and Visual Field Defects
Video by PhysioPathoPharmaco/YouTube
Visual field processing | Processing the Environment | MCAT | Khan Academy
Video by khanacademymedicine/YouTube
How to Take a Visual Field Examination? - Sheryl S. Wizov, COA
Video by WillsEye GlaucomaApp/YouTube
Visual Pathway and Lesions
Video by Armando Hasudungan/YouTube
What is Glaucoma? Explained using Animation.
Video by Devin Prabhakar/YouTube
Macular degeneration - Charles Bonnet syndrome (Visual Hallucinations)
Tmhlee
Advanced age-related macular degeneration with fibrosis
National Eye Institute, National Institutes of Health
Retinal Disparity
CNX Openstax
Advanced age-related macular degeneration
National Eye Institute, National Institutes of Health
Age-Related Macular Degeneration Overview
National Eye Institute, National Institutes of Health
Perimetry, a visual field test
Institute for Quality and Efficiency in Health Care (IQWiG)
Age-Related Macular Degeneration Overview
BruceBlaus
Age-Related Macular Degeneration Overview
National Eye Institute
Age-Related Macular Degeneration Overview
NEHEP
Age-Related Macular Degeneration Overview
Ralf Roletschek
Human Head Showing Visual Pathway
TheVisualMD
Topographic Mapping of the Retina onto the Visual Cortex
CNX Openstax
Ventral and Dorsal Visual Streams
CNX Openstax
Brain Revealing Visual Pathway
TheVisualMD
The optic disc, optic cup, and macula of a healthy 24 year old female (healthy rim tissue with a deep cup).
Eric Wiessner
Sensitive content
This media may include sensitive content
Muscle and Nerve of Human Eye
TheVisualMD
Macula of Retina
derivative work: Chmee2 (talk) Left_Retina.jpg: Hey Paul
Retina
Original uploader was Ratznium at en.wikipedia
Vestibulo-ocular Reflex
CNX Openstax
Optic Nerve - A bundle of more than 1 million nerve fibers that carries visual messages from the retina to the brain.
TheVisualMD
Partially Sectioned Human Eye Exposing front and back of the eye including the Retina
TheVisualMD
Human Eye
A Hoofring ncbi/nlm/nih
Vestibulo-ocular Reflex
CNX Openstax
5:29
Visual Neural Pathways and Visual Field Defects
PhysioPathoPharmaco/YouTube
4:10
Visual field processing | Processing the Environment | MCAT | Khan Academy
khanacademymedicine/YouTube
4:00
How to Take a Visual Field Examination? - Sheryl S. Wizov, COA
WillsEye GlaucomaApp/YouTube
6:12
Visual Pathway and Lesions
Armando Hasudungan/YouTube
1:10
What is Glaucoma? Explained using Animation.
Devin Prabhakar/YouTube
Eye Pressure Test
Eye Pressure Test
Also called: Intraocular Pressure (IOP) Measurement, Tonometry
Eye pressure, also called intraocular pressure (IOP), is a measurement of the fluid pressure inside the eye. Measuring it is like measuring blood pressure using a method called tonometry. Having eye pressure that’s too low or too high can damage your vision.
Eye Pressure Test
Also called: Intraocular Pressure (IOP) Measurement, Tonometry
Eye pressure, also called intraocular pressure (IOP), is a measurement of the fluid pressure inside the eye. Measuring it is like measuring blood pressure using a method called tonometry. Having eye pressure that’s too low or too high can damage your vision.
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Use the slider below to see how your results affect your
health.
mm Hg
10
21
Your result is Normal.
A normal result means your eye pressure is within the normal range. However, the thickness of your cornea can affect measurements. A corneal thickness measurement (pachymetry) is needed to get a correct pressure measurement.
Related conditions
The measurement of intraocular pressure (tonometry) is one of the most common eye examinations. The pressure inside the eyeball becomes too high if a fluid produced in the eye (called aqueous humor) cannot drain properly and starts to build up. An intraocular pressure of between 10 and 21 mmHg (millimeters of mercury) is considered to be normal in adults.
Various instruments can be used to measure the pressure in the eye. In what is known as applanation tonometry, the cornea is first numbed using eye drops. Then a small measuring device is placed against the surface of the cornea, putting a little pressure on the eye.
The device measures how much pressure is needed to flatten the cornea by 3 millimeters. This is a measure of the pressure inside the eye.
Intraocular pressure can also be measured using an approach known as non-contact tonometry. Here the pressure is measured by applying a short puff of air to the cornea. Neither of these examinations are painful.
Tonometry: MedlinePlus Medical Encyclopedia [accessed on Oct 03, 2018]
Eye Pressure Testing - American Academy of Ophthalmology [accessed on Oct 03, 2018]
What is low eye pressure and does it cause any damage to your eyes? - American Academy of Ophthalmology [accessed on Oct 03, 2018]
Five Common Glaucoma Tests | Glaucoma Research Foundation [accessed on Oct 03, 2018]
High Eye Pressure and Glaucoma | Glaucoma Research Foundation [accessed on Oct 03, 2018]
Tonometry: Purpose, Procedure, and Results [accessed on Oct 03, 2018]
IOP and Tonometry - EyeWiki [accessed on Oct 03, 2018]
Tonometry [accessed on Oct 03, 2018]
Intraocular pressure - Wikipedia [accessed on Oct 03, 2018]
Normal reference ranges can vary depending on the laboratory and the method used for testing. You must use the range supplied by the laboratory that performed your test to evaluate whether your results are "within normal limits."
Additional Materials (6)
Ocular tonometry
Goldmann mires : Semicircles seen during Goldmann tonometry through slit lamp
Image by Manimury
Ocular tonometry
The PASCAL Dynamic Contour Tonometer
Image by Tonywirthlin at English Wikipedia
Vestibulo-ocular Reflex
Connections between the vestibular system and the cranial nerves controlling eye movement keep the eyes centered on a visual stimulus, even though the head is moving. During head movement, the eye muscles move the eyes in the opposite direction as the head movement, keeping the visual stimulus centered in the field of view.
Image by CNX Openstax
Neuro-ocular syphilis
This funduscopic image reveals the effects of late neuro-ocular syphilis on the optic disk and retina. Note the typical features of neuro-ocular syphilis, which includes severe optic nerve atrophy, and chorioretinitis, or inflammation of the choroidal and neural layers of the retina.
Image by CDC/ Susan Lindsley
SVC Insight - Tonometry
Video by Linda Young/YouTube
Tonometer
A noncontact tonometer scans the eye of U.S. Air Force Staff Sgt. Timothy Gallagher, 23d Wing public affairs broadcast journalist, during an optometry appointment Feb. 4, 2014, at Moody Air Force Base, Ga. The tonometer is used to screen for glaucoma. (U.S. Air Force photo by Airman 1st Class Ceaira Tinsley/Released)
Image by U.S. Air Force photo by Airman 1st Class Ceaira Tinsley/Released
Ocular tonometry
Manimury
Ocular tonometry
Tonywirthlin at English Wikipedia
Vestibulo-ocular Reflex
CNX Openstax
Neuro-ocular syphilis
CDC/ Susan Lindsley
6:01
SVC Insight - Tonometry
Linda Young/YouTube
Tonometer
U.S. Air Force photo by Airman 1st Class Ceaira Tinsley/Released
Slit-Lamp Exam
Slit-Lamp Exam
Also called: Biomicroscopy, Slit Lamp Exam, Slit Lamp Test
A slit lamp exam is an eye examination using an instrument that combines a low-power microscope with a light source that makes a narrow beam of light. The instrument may be used to examine the retina, optic nerve, and other parts of the eye.
Slit-Lamp Exam
Also called: Biomicroscopy, Slit Lamp Exam, Slit Lamp Test
A slit lamp exam is an eye examination using an instrument that combines a low-power microscope with a light source that makes a narrow beam of light. The instrument may be used to examine the retina, optic nerve, and other parts of the eye.
{"label":"Slit-Lamp Exam Reference Range","scale":"lin","step":0.25,"hideunits":true,"items":[{"flag":"normal","label":{"short":"Normal","long":"Normal","orientation":"horizontal"},"values":{"min":0,"max":1},"text":"A normal result indicates that the eyelashes, eyelids, and lining of the eyelids (conjunctiva) look normal. All of the structures inside the eye are found to be normal.","conditions":[]},{"flag":"abnormal","label":{"short":"Abnormal","long":"Abnormal","orientation":"horizontal"},"values":{"min":1,"max":2},"text":"Abnormal findings may include infections, diabetic complications, remnants of previous inflammatory problems, extreme allergies and cataracts.","conditions":["Cataract","Injury to the cornea","Dry eye syndrome","Retinal detachment","Retinal vessel occlusion","Retinitis pigmentosa","Uveitis"]}],"value":0.5}[{"normal":0},{"abnormal":0}]
Use the slider below to see how your results affect your
health.
Your result is Normal.
A normal result indicates that the eyelashes, eyelids, and lining of the eyelids (conjunctiva) look normal. All of the structures inside the eye are found to be normal.
Related conditions
https://medlineplus.gov/ency/article/003880.htm [accessed on Feb 15, 2019]
https://www.cancer.gov/publications/dictionaries/cancer-terms/def/slit-lamp-eye-exam [accessed on Feb 15, 2019]
https://www.verywellhealth.com/eye-exam-tests-and-procedures-3421854 [accessed on Feb 15, 2019]
Normal reference ranges can vary depending on the laboratory and the method used for testing. You must use the range supplied by the laboratory that performed your test to evaluate whether your results are "within normal limits."
Additional Materials (20)
Fleck dystrophy
Fleck corneal dystrophy. Appearance of the cornea by slit-lamp biomicroscopy (left image) and by confocal microscopy (right image) (Courtesy Dr. Charles N. McGhee). Klintworth Orphanet Journal of Rare Diseases
Image by Klintworth GK
Sensitive content
This media may include sensitive content
Slit Lamp Exam
Maj. Ivy Madson, 99th Air Base Squadron optometry flight commander, uses a Slit Lamp to examine the interior of the eye during an exam for Airman 1st Class Hunter, 18th Reconnaissance Squadron Airman, Jan. 13, 2015, at Creech Air Force Base, Nevada. The Creech Medical Aid Station now offers optometry services to all personnel assigned to Creech AFB Tuesdays from 7:30 a.m. to 3 p.m. (Last names have been withheld for security purposes). (U.S. Air Force photo by Staff Sgt. Adawn Kelsey/Released)
Image by U.S. Air Force photo by Staff Sgt. Adawn Kelsey/Released
Cystinosis
Slit-lamp photographs of three-year-old patient with nephropathic cystenosis before (left) and after (right) cysteamine eyedrop therapy. Treatment targeting metabolic defect dramatically dissolves painful crystals in the eye's cornea.
Image by NIH Clinical Center Location: National Institutes of Health, Bethesda, MD
Slit Lamp Photo of Eye
Slit Lamp Photo of Eye
Image by U.S. Air Force photo by Senior Airman Zachary Hada/Released
How is a cataract detected?
Slit lamp image of the cornea, iris and lens (showing mild cataract)
Image by Baristoprak~commonswiki
Lisch nodules
Lisch nodules on surface of iris. The patient was a 14-year-old male with pulsating exophthalmos of the left eye and poor vision of this highly myopic left eye. There was also some ptosis of the left eye with mild puffiness. Upward gaze of the left eye was limited. Slit lamp examination showed multiple, slightly raised nodules of the right iris.
Image by National Eye Institute
Von Hippel-Lindau Disease
Von Hippel-Lindau Disease : Slit lamp photograph showing retinal detachment in Von Hippel-Lindau disease
Image by National Eye Institute of the NIH
Stress female student studying
Young female in a green shirt, viewed from the back at left, concentrating on work materials at a desk with a lamp lamp. Computer monitor, phone and bulletin board are visible, as are stacks of books and papers. Image supports content about identifying harmful patterns in your life, including work-related stress, so you can plan to replace them with more beneficial patterns
Image by TheVisualMD
What are the symptoms of a cataract?
Slit lamp camera view of Cataract in Human Eye
Image by Rakesh Ahuja, MD
Congenital stromal corneal dystrophy
The cornea is particularly opaque in the anterior stroma by slit-lamp biomicroscopy.
Image by Klintworth GK
Ocular tonometry
Goldmann mires : Semicircles seen during Goldmann tonometry through slit lamp
Image by Manimury
Cystinosis
The patient was a 4 1/2-year-old male who looked about 2 1/2 years old at his first visit. He was admitted to the hospital because of poor growth and polydipsia. The patient was admitted to the hospital in uremia and coma. An examination of the cornea showed the surface and the immediate subepithelial region to be studded with golden-brown, fine scintillating particles, uniformly distributed throughout the entire cornea, but possibly sparing the most peripheral zone ([1]). The stroma appeared to be clear, but the posterior surface of the cornea showed the same type of particles in the lower nasal quadrant, although sparser than was the case on the surface. There were apparently also some crystals in the conjunctiva. The tentative diagnosis was cystinosis or Fanconi's syndrome, but unlike the other cases reported, the crystals appeared to be at the anterior and posterior surfaces and not in the stroma. The patient was seen again at age 8 years old, when he was back in the hospital. The cornea still contained crystals ([2]). The only noteworthy event in the recent history was a nosebleed of 20 hours duration. His non-protein nitrogen was 140 and he appeared very pale, but he was lively and alert. He had a persistent anemia and potassium depletion. Presumably both the anemia and the hemorrhagic diathesis were attributed to uremia. The patient died in the hospital. Noteworthy was the fact that his three siblings all showed clear corneas without crystals. However, the youngest was age three months and when she was examined again at age two years, she had abundant crystals and nephropathic cystinosis.
Image by National Eye Institute
What are the risks of cataract surgery?
Royal Australian Navy Lt. Elizabeth Livingstone and Singapore army Maj. Paul Zhao, both doctors embarked aboard the Military Sealift Command hospital ship USNS Mercy (T-AH 19), perform cataract surgery on a Vietnamese patient aboard Mercy during a Pacific Partnership 2010 visit to Quy Nhon, Vietnam. Pacific Partnership is the fifth in a series of annual U.S. Pacific Fleet humanitarian and civic assistance endeavors to strengthen regional partnerships.
Image by U.S. Navy photo by Mass Communication Specialist 2nd Class Eddie Harrison
Sensitive content
This media may include sensitive content
Fundoscopic (Ophthalmoscopic) Exam
Dr. (Maj.) Michael Bogaard, 509th Medical Operations Squadron optometrist, uses a binocular indirect ophthalmoscope to perform an eye assessment on Senior Airman Jeffrey Afemon, 509th MDOS public health technician, in the optometry clinic at Whiteman Air Force Base, Mo., Sept. 4, 2013. The ophthalmoscope helps focus the light inside the patient’s eye and provides an image that the doctor uses to judge the health of the retina.
Image by U.S. Air Force photo by Staff Sgt. Nick Wilson/Released
Slit lamp photograph showing c in Von Hippel-Lindau disease
Slit lamp photograph showing retinal detachment in Von Hippel-Lindau disease.
Image by National Eye Institute/National Institutes of Health
Neurofibromatosis type 1(>90% of cases) together with scattered café au lait pigmented skin lesions and multiple neurifibromas (superficial or deep) in skin or other organs.
Lisch nodules are numerous nodules of dendritic melanocytes in aggregates within the iris. They are brown-yellow, round shape, raised papules as seen with slit lamp examination in the iris of patients with Neurofibromatosis type 1(>90% of cases) together with scattered café au lait pigmented skin lesions and multiple neurifibromas (superficial or deep) in skin or other organs. Similar nodules are also found in Watson syndrome which is in addition characterized by macrocephaly, pulmonary stenosis, short status and low intelligence. No treatment is required but a close follow-up of main diseases is mandatory for avoiding any serious complications.
Image by Dimitrios Malamos
Ocular tonometry
The PASCAL Dynamic Contour Tonometer
Image by Tonywirthlin at English Wikipedia
Slit Lamp Exam and Techniques
Video by iSEE/YouTube
Slit Lamp Examination (Biomicroscopy) in English
Video by TheIACLE/YouTube
Slit Lamp Exam
Video by Brian Nelson/YouTube
Fleck dystrophy
Klintworth GK
Sensitive content
This media may include sensitive content
Slit Lamp Exam
U.S. Air Force photo by Staff Sgt. Adawn Kelsey/Released
Cystinosis
NIH Clinical Center Location: National Institutes of Health, Bethesda, MD
Slit Lamp Photo of Eye
U.S. Air Force photo by Senior Airman Zachary Hada/Released
How is a cataract detected?
Baristoprak~commonswiki
Lisch nodules
National Eye Institute
Von Hippel-Lindau Disease
National Eye Institute of the NIH
Stress female student studying
TheVisualMD
What are the symptoms of a cataract?
Rakesh Ahuja, MD
Congenital stromal corneal dystrophy
Klintworth GK
Ocular tonometry
Manimury
Cystinosis
National Eye Institute
What are the risks of cataract surgery?
U.S. Navy photo by Mass Communication Specialist 2nd Class Eddie Harrison
Sensitive content
This media may include sensitive content
Fundoscopic (Ophthalmoscopic) Exam
U.S. Air Force photo by Staff Sgt. Nick Wilson/Released
Slit lamp photograph showing c in Von Hippel-Lindau disease
National Eye Institute/National Institutes of Health
Neurofibromatosis type 1(>90% of cases) together with scattered café au lait pigmented skin lesions and multiple neurifibromas (superficial or deep) in skin or other organs.
Dimitrios Malamos
Ocular tonometry
Tonywirthlin at English Wikipedia
4:58
Slit Lamp Exam and Techniques
iSEE/YouTube
13:20
Slit Lamp Examination (Biomicroscopy) in English
TheIACLE/YouTube
7:10
Slit Lamp Exam
Brian Nelson/YouTube
Schirmer Test
Schirmer Test
Also called: Basal Secretion Test, Dry Eye Test, Tearing Test
A Schirmer test tells your eye doctor how quickly your eyes make tears. Your eye doctor will put a small piece of paper on the edge of your eyelid and see how long it takes for your body to make tears.
Schirmer Test
Also called: Basal Secretion Test, Dry Eye Test, Tearing Test
A Schirmer test tells your eye doctor how quickly your eyes make tears. Your eye doctor will put a small piece of paper on the edge of your eyelid and see how long it takes for your body to make tears.
{"label":"Schirmer test reference range","scale":"lin","step":0.1,"hideunits":false,"items":[{"flag":"abnormal","label":{"short":"S","long":"Severe","orientation":"horizontal"},"values":{"min":0,"max":5},"text":"Wetting of less than 5 mm is indicative of deficient tear production, but is not necessarily diagnostic of Sj\u00f6gren\u2019s syndrome.","conditions":["Dry eye","Aging","Blepharitis","Climate change","Corneal ulcer","Corneal infection","Eye infection","Laser vision correction (LASIK)","Leukemia","Lymphoma","Rheumatoid arthritis","Sj\u00f6gren syndrome","Vitamin A deficiency"]},{"flag":"abnormal","label":{"short":"M","long":"Moderate","orientation":"horizontal"},"values":{"min":5,"max":10},"text":"Less than 10 mm of moisture indicates you probable have dry eye syndrome.","conditions":["Dry eye","Aging","Blepharitis","Climate change","Corneal ulcer","Corneal infection","Eye infection","Laser vision correction (LASIK)","Leukemia","Lymphoma","Rheumatoid arthritis","Sj\u00f6gren syndrome","Vitamin A deficiency"]},{"flag":"normal","label":{"short":"N","long":"Normal","orientation":"horizontal"},"values":{"min":10,"max":15},"text":"More than 10 mm of moisture on the filter paper after 5 minutes is a sign of normal tear production. Both eyes normally release the same amount of tears.","conditions":[]},{"flag":"abnormal","label":{"short":"H","long":"High","orientation":"horizontal"},"values":{"min":15,"max":30},"text":"If your eyes produce more than 10 to 15 mm of moisture, further tests may also be required to determine the cause of your watery eyes.","conditions":["Watery eyes"]}],"units":[{"printSymbol":"mm","code":"mm","name":"millimeter"}],"value":12.5}[{"abnormal":1},{"abnormal":0},{"normal":0},{"abnormal":0}]
Use the slider below to see how your results affect your
health.
mm
5
10
15
Your result is Normal.
More than 10 mm of moisture on the filter paper after 5 minutes is a sign of normal tear production. Both eyes normally release the same amount of tears.
Related conditions
https://nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/dry-eye/testing-dry-eye [accessed on Sep 15, 2019]
https://medlineplus.gov/ency/article/003501.htm [accessed on Sep 15, 2019]
https://www.medicalnewstoday.com/articles/315974.php [accessed on Sep 15, 2019]
https://www.hopkinssjogrens.org/disease-information/diagnosis-sjogrens-syndrome/schirmers-test/ [accessed on Sep 15, 2019]
https://www.healthline.com/health/schirmers-test#results [accessed on Sep 15, 2019]
https://en.wikipedia.org/wiki/Schirmer%27s_test [accessed on Sep 15, 2019]
Tear Break-Up Time Test
Tear Break-Up Time Test
Also called: TBUT
A tear break-up time (TBUT) test checks how long your tear film (layer of tears on your eyes) lasts after you blink. If your tear film does not last long, you may have dry eye.
Tear Break-Up Time Test
Also called: TBUT
A tear break-up time (TBUT) test checks how long your tear film (layer of tears on your eyes) lasts after you blink. If your tear film does not last long, you may have dry eye.
{"label":"Tear Break-Up Time Reference Range","scale":"lin","step":0.1,"hideunits":false,"units":[{"printSymbol":"s","code":"s","name":"second - time"}],"items":[{"flag":"abnormal","label":{"short":"Low","long":"Low","orientation":"horizontal"},"values":{"min":0,"max":5},"text":"A short tear break-up time is a sign of a poor tear film and the longer it takes the more stable the tear film.","conditions":["Dry eye"]},{"flag":"abnormal","label":{"short":"Marginal","long":"Marginal","orientation":"horizontal"},"values":{"min":5,"max":10},"text":"A short tear break-up time is a sign of a poor tear film and the longer it takes the more stable the tear film.","conditions":["Dry eye"]},{"flag":"normal","label":{"short":"Normal","long":"Normal","orientation":"horizontal"},"values":{"min":10,"max":15},"text":"Tear film break-up time (TBUT) is a method for determining the stability of the tear film and checking evaporative dry eye. Generally, >10 seconds is thought to be normal. ","conditions":[]}],"value":12.5}[{"abnormal":1},{"abnormal":0},{"normal":0}]
Use the slider below to see how your results affect your
health.
s
5
10
Your result is Normal.
Tear film break-up time (TBUT) is a method for determining the stability of the tear film and checking evaporative dry eye. Generally, >10 seconds is thought to be normal.
Related conditions
https://nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/dry-eye/testing-dry-eye [accessed on Sep 15, 2019]
https://medlineplus.gov/ency/article/000426.htm [accessed on Sep 15, 2019]
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3570579/ [accessed on Sep 15, 2019]
Normal reference ranges can vary depending on the laboratory and the method used for testing. You must use the range supplied by the laboratory that performed your test to evaluate whether your results are "within normal limits."
Ophthalmoscopy
Ophthalmoscopy
Also called: Funduscopy, Retinal Examination
Ophthalmoscopy is an exam that uses a magnifying lens and a light to check the fundus of the eye (back of the inside of the eye, including the retina and optic nerve). Ophthalmoscopy may be used to check for eye problems, such as glaucoma, macular degeneration, eye cancer, optic nerve problems, or eye injury.
Ophthalmoscopy
Also called: Funduscopy, Retinal Examination
Ophthalmoscopy is an exam that uses a magnifying lens and a light to check the fundus of the eye (back of the inside of the eye, including the retina and optic nerve). Ophthalmoscopy may be used to check for eye problems, such as glaucoma, macular degeneration, eye cancer, optic nerve problems, or eye injury.
{"label":"Ophthalmoscopy Reference Range","scale":"lin","step":0.25,"hideunits":true,"items":[{"flag":"normal","label":{"short":"Normal","long":"Normal","orientation":"horizontal"},"values":{"min":0,"max":1},"text":"The retina, blood vessels, and the optic disc appear normal.","conditions":[]},{"flag":"abnormal","label":{"short":"Abnormal","long":"Abnormal","orientation":"horizontal"},"values":{"min":1,"max":2},"text":"Abnormal results may be seen on ophthalmoscopy with a variety of conditions.","conditions":["CMV retinitis","Diabetes","Glaucoma","High blood pressure","Loss of sharp vision due to macular degeneration","Melanoma of the eye","Optic nerve problems","Retinal tear or retinal detachment"]}],"value":0.5}[{"normal":0},{"abnormal":0}]
Use the slider below to see how your results affect your
health.
Your result is Normal.
The retina, blood vessels, and the optic disc appear normal.
Related conditions
https://medlineplus.gov/ency/article/003881.htm [accessed on Feb 15, 2019]
https://www.verywellhealth.com/eye-exam-tests-and-procedures-3421854 [accessed on Feb 15, 2019]
Normal reference ranges can vary depending on the laboratory and the method used for testing. You must use the range supplied by the laboratory that performed your test to evaluate whether your results are "within normal limits."
Additional Materials (50)
ophthalmoscopy video
Video by CHECT UK/YouTube
Approach to Fundoscopy / Ophthalmoscopy
Video by Stanford Medicine 25/YouTube
Veterinary Medicine
"GUANTANAMO BAY, Cuba %u2013 Army Sgt. Ardicio Galvao, an animal care non-commissioned officer at the Guantanamo Bay Veterinary Treatment Facility, performs an eye examination on a kitten up for adoption.
Image by The National Guard
Retinoblastoma - Treatment Option Overview
Retinoblastoma (Rb) is a rapidly developing cancer that develops from the immature cells of aretina, the light-detecting tissue of the eye and is the most common malignant tumor of the eye in children.
Image by Tero Kivela
ophtalmogram of the retina, optic nerve, fovea and macula. The spot to the left (temporal side) of the centre is the macula.
Self made ophtalmogram of the retina of the right eye. It shows the optic disc as a bright area on the right (nasal side) where blood vessels converge. The spot to the left (temporal side) of the centre is the macula. The grey, more diffuse spot in the centre is a shadow artifact.
Image by Ske.
Diabetic retinopathy - Diabetic Eye Disease NIDDK
Proliferative retinopathy Description: Proliferative retinopathy, an advanced form of diabetic retinopathy, occurs when abnormal new blood vessels and scar tissue form on the surface of the retina.
Image by National Eye Institute, National Institutes of Health
Retinitis
Fundus, photograph-CMV retinitis
Image by National Eye Institute, National Institutes of Health
Age Related Macular degeneration - How is AMD detected?
Description: A fundus photo showing intermediate age-related macular degeneration.
Image by National Eye Institute, National Institutes of Health
Fluorescein angiography
Fluorescein retinography of a 33 years old patient (right eye), showing the optical disc at the inferior right quadrant and the macula lutea at the inferior left quadrant (darker spot). No anomalies detected.
Image by Mekhahertz
Age-Related Macular Degeneration Overview
Macular Degeneration
Image by Ralf Roletschek
Retinoblastoma - Treatment Option Overview
Ocular fundus aspect of retinoblastoma
Image by Aerts, I, Lumbroso-Le Rouic, L, Marion Gauthier-Villars, M, Brisse, H, Doz, F, Desjardins, L. Retinoblastoma.
Cytomegalovirus retinitis
Fundus photograph of CMV retinitis
Image by National Eye Institute, National Institutes of Health
Macular degeneration - Charles Bonnet syndrome (Visual Hallucinations)
This image shows an eye fundus viewed through a retinal camera, with signs of macular degeneration
Image by Tmhlee
Scanning laser ophthalmoscopy
Retinal image of a left eye via Optos Optomap.
Image by Modified by Overand - Original by Judgesurreal777
In background retinopathy, a slight deterioration in the small blood vessels of the retina, portions of the vessels may swell and leak fluid into the surrounding retinal tissue.
Retinopathy in fundus of eye
Image by National Eye Institute, National Institutes of Health
Optic Nerve
Healthy optic nerve
Image by Esteve.olm
Leber Congenital Amaurosis
Retina Photo of LCA : Retina photo of a patient with Leber congenital amaurosis (LCA), an inherited retinal disease that causes severe visual impairment early in childhood. Special gene testing is necessary to determine if the patient has the RPE65-associated type of the disease.
Image by National Eye Institute, National Institutes of Health.
Retinopathy of Prematurity (Small Animation)
Retinopathy of Prematurity (ROP)
Image by National Eye Institute/NIH
central retinal artery
Image by self
Drusen
Drusen in Optical Coherence Tomography
Image by Ipoliker
Chloroquine retinopathy
Chloroquine retinopathy in the left eye of a 55-year-old woman who had taken chloroquine for rheumatoid arthritis for more than 4 years, with an estimated total dose of 365 gr (250 mg daily). She first presented with a history of gradually decreasing visual acuity without any other symptoms approximately two years earlier. The latest examination revealed that her visual acuity was 30/200 right eye and 60/200 left eye. Left image shows typical bull's eye sign and right image is the fluorescien angiogram of the same eye showing increased fluorescence in the macular area and round-shaped blocked fluorescence in the central fovea.
Image by Doctors:Xiaoyun Ma, Liang Yan, Linping He Dongyi He, Hao Lu from Shanghai, China
Cone dystrophy
Fundus of cone rod dystrophy : Fundus of a 34 year-old patient with cone rod dystrophy due to Spinocerebellar Ataxia Type 7 (SCA7). Note that the macular area, and also the mid periphery, are atrophic.
Image by Christian P Hamel
Bardet-Biedl syndrome
Bardet-Biedl syndrome : Fundus of a 31 year-old patient with Bardet Biedl syndrome. The peripheral retina does not show any large lesion but the macula is atrophic.
Image by Beales PL, Elcioglu N, Woolf AS, Parker D, Flinter FA
Diabetic Retinopathy
Fundus photo showing scatter laser surgery for diabetic retinopathy.
Image by National Eye Institute, National Institutes of Health
Central retinal vein occlusion
Branch retinal vein occlusion (BRVO) Color fundus photograph of the left eye shows occlusion of the superotemporal branch of retinal vein resulting in intraretinal hemorrhages and retinal exudates in the corresponding sector of retina.
Image by Kim Baxter, Cambridge University Hospitals NHS Foundation Trust, Wellcome Images
Infant Eye cross section
Cross-section of the healthy eye of an infant, showing a retina that is in perfect condition, having never been exposed to smoke-borne toxins that would compromise circulation and result in retinal damage. Image supports content showing the health benefits of smoke cessation.
Image by TheVisualMD
Chorioretinitis
Chorioretinitis AIDS : Photograph taken of the back of the eye of an AIDS patient with chorioretinitis, which is an inflammation of the retina and choroid (thin pigmented vascular coat of the eye).
Image by NCI
Drusen
Macular Soft Drusen : Fundus image of macular soft Drusen in the right eye of a 70 year old male
Image by Ipoliker
Ocular larva migrans granuloma via toxocara canis infection from newborn puppies
Ocular larva migrans granuloma via toxocara canis infection from newborn puppies
Image by enableuser
Smoking and the eye
The effects of cigarette smoke have been associated with many ailments, including two sight-threatening eye conditions. Left, an eye that shows signs of macular degeneration. The yellow or off-white deposits, called drusen, that form beneath the retinal layer are a common sign that macular degeneration is in progress. Right, an eye with a cataract. The lens of the eye is usually crystal clear to allow unobstructed vision. Cataract also means \"waterfall.\" Doctors have likened the difficulty of seeing through a lens with a cataract to trying to see clearly through a rushing waterfall.
Image by TheVisualMD
Tuberous Sclerosis - What is the prognosis?
The prognosis for individuals with TSC is highly variable and depends on the severity of symptoms. Those individuals with mild symptoms usually do well and have a normal life expectancy, while paying attention to TSC-specific issues. Individuals who are severely affected can suffer from severe mental retardation and persistent epilepsy.
Image by National Eye Institute of the NIH
Retinitis pigmentosa
Fundus of patient with retinitis pigmentosa, end stage: Fundus of patient with retinitis pigmentosa, end stage (Pigment deposits are present all over the retina. Retinal vessels are very thin and optic disc is pale.
Image by Christian Hamel
Retinopathy - Cerebroretinal microangiopathy with calcifications and cysts. Exudative retinopathy and vitreos hemorrhage: A fundus photograph of a child with cerebroretinal microangiopathy with calcifications and cysts, in which red vitreous bleeding and yellowish lipid under a detached retina are seen.
Cerebroretinal microangiopathy with calcifications and cysts. Exudative retinopathy and vitreos hemorrhage: A fundus photograph of a child with cerebroretinal microangiopathy with calcifications and cysts from a mutation in the CTC1 gene, in which red vitreous bleeding and yellowish lipid under a detached retina are seen.
Image by Tero Kivela, MD, FEBO
Left, an eye that shows signs of macular degeneration. Right, an eye with a cataract.
This image features two sight-threatening eye conditions. Left, an eye that shows signs of macular degeneration. The yellow or off-white deposits, called drusen, that form beneath the retinal layer are a common sign that macular degeneration is in progress. Right, an eye with a cataract. The lens of the eye is usually crystal clear to allow unobstructed vision. Cataract also means \"waterfall.\" Doctors have likened the difficulty of seeing through a lens with a cataract to trying to see clearly through a rushing waterfall.
Image by TheVisualMD
Presumed Ocular Histoplasmosis Syndrome
Retinal photograph of ocular histoplasmosis
Image by Wickedthought
Neuro-ocular syphilis
This funduscopic image reveals the effects of late neuro-ocular syphilis on the optic disk and retina. Note the typical features of neuro-ocular syphilis, which includes severe optic nerve atrophy, and chorioretinitis, or inflammation of the choroidal and neural layers of the retina.
Image by CDC/ Susan Lindsley
Fundus Photography
An eye care professional takes fundus autofluorescence photographs to study the retina.
Image by National Eye Institute, National Institutes of Health
Complications of diabetes mellitus
Diabetes and Small Vessel Disease : High levels of blood glucose damage the smallest vessels in your body, the capillaries, just as they do the larger vessels. One cause of this damage may be the high levels of advanced glycation end products (AGEs) that glucose creates inside capillary cells.
Image by TheVisualMD
Cross-section of retina, close-up of the photoreceptors
DHA and vision
Image by TheVisualMD
Eye with Diabetic Retinopathy
Eye with cross section revealing diabetic retinopathy; the damaged retina due to diabetes. The visible damaged includes yellow patches of fatty deposits and tiny dark dots, or microaneurysms.
Image by TheVisualMD
DiabeticRetinopathy
Diabetic Retinopathy
Image by Blausen.com staff (2014). "Medical gallery of Blausen Medical 2014
Macula of Retina
photograph of the retina of the human eye, with overlay diagrams showing the positions and sizes of the macula, fovea, and optic disc
Image by National Eye Institute of the NIH
Partially Sectioned Human Eye Exposing front and back of the eye including the Retina
Three-dimensional visualization reconstructed from human data. Anteriolateral view of a partially sectioned eye, as well as associated eye muscles. As well as being protected by the bony orbital cavity of the skull, the eyeball is anchored in place by several thin strap muscles that attach to virtually every one of its sides except the front. These muscles tug in concert, allowing the eye to move in any direction to track objects. The clear cornea covers and protects the front exterior of the eye while the colored iris dilates and constricts to insure the proper amount of light is striking the back of the eye. The lens contorts to focus the incoming light back to the retina, which covers roughly the entire back half of the eye. Special cells embedded within the retina are responsible for the sensation of light: the cones, for color perception, and rods, for black and white perception. Electrical nerve impulses are channeled into the optic nerve at the back of the eye to the visual cortex in the brain.
Image by TheVisualMD
Month 1
A newborn sleeps 12-20 hours per day, but don't let that fool you: your baby will go through enormous transformations in his first month. Your womb was safe, warm, dark, and quiet. Now your baby has to adapt to the outside world, full of bright lights, noises, and unfamiliar sensations.
Image by TheVisualMD
Retina close-up
A picture of a patient’s retina is displayed at the optometry clinic March 11, 2016, at Malmstrom Air Force Base, Mont. The clinic is the only one in Montana that has a retinal imagining device called an Optos, used to look at the retina without diluting it. (U.S. Air Force photo/Senior Airman Jaeda Tookes)
Image by U.S. Air Force photo/Senior Airman Jaeda Tookes
Macula of Retina
Animation of Optic cup and macula - 3D motion parallax -The optic cup and macula of a healthy 24 year old female. Image is released to wikimedia commons with patient consent. GIF displays a three dimensional view of the cup via motion parallax. Imaged with a non-mydriatic fundus camera at Pacific University College of Optometry.
Image by Eric Wiessner
Fundus photo showing focal laser surgery for diabetic retinopathy
Fundus photo showing focal laser surgery for diabetic retinopathy.
Image by National Eye Institute, National Institutes of Health
Eye with Diabetic Retinopathy
Image showing diabetic retinopathy , a condition caused by diabetes and affects the capillaries of the retina causing eventual blindness unless treated.
Image by TheVisualMD
Retina showing reticular pseudodrusen - early age-related macular degeneration (AMD)
A new clinical study led by the National Eye Institute (NEI), part of the National Institutes of Health, will follow 500 people over five years to learn more about the natural history of early age-related macular degeneration (AMD). By using the latest technologies to visualize structures within the eye and measure their function, researchers hope to identify biomarkers of disease progression, well before it advances to late-stage disease and causes vision loss. AMD is the leading cause of vision impairment and blindness among people age 50 and older in the United States.
Image by NIH Image Gallery
Hypotrichosis with juvenile macula dystrophy
ophthalmoscopy left eye of a 5-year-old boy with HJMD
Image by BazokaSmurf
9:33
ophthalmoscopy video
CHECT UK/YouTube
8:56
Approach to Fundoscopy / Ophthalmoscopy
Stanford Medicine 25/YouTube
Veterinary Medicine
The National Guard
Retinoblastoma - Treatment Option Overview
Tero Kivela
ophtalmogram of the retina, optic nerve, fovea and macula. The spot to the left (temporal side) of the centre is the macula.
Ske.
Diabetic retinopathy - Diabetic Eye Disease NIDDK
National Eye Institute, National Institutes of Health
Retinitis
National Eye Institute, National Institutes of Health
Age Related Macular degeneration - How is AMD detected?
National Eye Institute, National Institutes of Health
Fluorescein angiography
Mekhahertz
Age-Related Macular Degeneration Overview
Ralf Roletschek
Retinoblastoma - Treatment Option Overview
Aerts, I, Lumbroso-Le Rouic, L, Marion Gauthier-Villars, M, Brisse, H, Doz, F, Desjardins, L. Retinoblastoma.
Cytomegalovirus retinitis
National Eye Institute, National Institutes of Health
Macular degeneration - Charles Bonnet syndrome (Visual Hallucinations)
Tmhlee
Scanning laser ophthalmoscopy
Modified by Overand - Original by Judgesurreal777
In background retinopathy, a slight deterioration in the small blood vessels of the retina, portions of the vessels may swell and leak fluid into the surrounding retinal tissue.
National Eye Institute, National Institutes of Health
Optic Nerve
Esteve.olm
Leber Congenital Amaurosis
National Eye Institute, National Institutes of Health.
Retinopathy of Prematurity (Small Animation)
National Eye Institute/NIH
central retinal artery
self
Drusen
Ipoliker
Chloroquine retinopathy
Doctors:Xiaoyun Ma, Liang Yan, Linping He Dongyi He, Hao Lu from Shanghai, China
Cone dystrophy
Christian P Hamel
Bardet-Biedl syndrome
Beales PL, Elcioglu N, Woolf AS, Parker D, Flinter FA
Diabetic Retinopathy
National Eye Institute, National Institutes of Health
Central retinal vein occlusion
Kim Baxter, Cambridge University Hospitals NHS Foundation Trust, Wellcome Images
Infant Eye cross section
TheVisualMD
Chorioretinitis
NCI
Drusen
Ipoliker
Ocular larva migrans granuloma via toxocara canis infection from newborn puppies
enableuser
Smoking and the eye
TheVisualMD
Tuberous Sclerosis - What is the prognosis?
National Eye Institute of the NIH
Retinitis pigmentosa
Christian Hamel
Retinopathy - Cerebroretinal microangiopathy with calcifications and cysts. Exudative retinopathy and vitreos hemorrhage: A fundus photograph of a child with cerebroretinal microangiopathy with calcifications and cysts, in which red vitreous bleeding and yellowish lipid under a detached retina are seen.
Tero Kivela, MD, FEBO
Left, an eye that shows signs of macular degeneration. Right, an eye with a cataract.
TheVisualMD
Presumed Ocular Histoplasmosis Syndrome
Wickedthought
Neuro-ocular syphilis
CDC/ Susan Lindsley
Fundus Photography
National Eye Institute, National Institutes of Health
Complications of diabetes mellitus
TheVisualMD
Cross-section of retina, close-up of the photoreceptors
TheVisualMD
Eye with Diabetic Retinopathy
TheVisualMD
DiabeticRetinopathy
Blausen.com staff (2014). "Medical gallery of Blausen Medical 2014
Macula of Retina
National Eye Institute of the NIH
Partially Sectioned Human Eye Exposing front and back of the eye including the Retina
TheVisualMD
Month 1
TheVisualMD
Retina close-up
U.S. Air Force photo/Senior Airman Jaeda Tookes
Macula of Retina
Eric Wiessner
Fundus photo showing focal laser surgery for diabetic retinopathy
National Eye Institute, National Institutes of Health
Eye with Diabetic Retinopathy
TheVisualMD
Retina showing reticular pseudodrusen - early age-related macular degeneration (AMD)
NIH Image Gallery
Hypotrichosis with juvenile macula dystrophy
BazokaSmurf
Retinoscopy
Retinoscopy
Also called: Ret, Shadow Test, Skiametry, Skiascopy
Retinoscopy is an objective determination of the refractive state of the eye (nearsightedness, farsightedness, astigmatism). By using a retinoscope, the amount of correction and the power of lens needed can be determined.
Retinoscopy
Also called: Ret, Shadow Test, Skiametry, Skiascopy
Retinoscopy is an objective determination of the refractive state of the eye (nearsightedness, farsightedness, astigmatism). By using a retinoscope, the amount of correction and the power of lens needed can be determined.
Retinoscopy is an accurate objective measurement of the refractive state of the eye, such as the degree of nearsightedness, farsightedness or astigmatism. It uses light reflected off the back of the eye and hand-held lenses to measure refractive error.
A retinoscopy can be especially useful in determining refractive error in very young children and infants or people with special needs, as it requires minimal cooperation.
Refractive errors occur when the shape of the eye prevents light from focusing directly on the retina. The length of the eyeball (longer or shorter), changes in the shape of the cornea, or aging of the lens can all cause refractive errors.
The most common types of refractive errors are myopia, hyperopia, and astigmatism.
Myopia (nearsightedness) is a condition where objects up close appear clearly, while objects far away appear blurry. With myopia, light comes to focus in front of the retina instead of on the retina.
Hyperopia (farsightedness) is a common type of refractive error where distant objects may be seen more clearly than objects that are near. However, people experience hyperopia differently. Some people may not notice any problems with their vision, especially when they are young. For people with significant hyperopia, vision can be blurry for objects at any distance, near or far.
Astigmatism is a condition in which the eye does not focus light evenly onto the retina, the light-sensitive tissue at the back of the eye. This can cause images to appear blurry and stretched out.
https://www.aapos.org/terms/conditions/95 [accessed on Feb 14, 2019]
https://nei.nih.gov/health/errors [accessed on Feb 14, 2019]
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5646585/ [accessed on Feb 14, 2019]
https://www.aao.org/young-ophthalmologists/yo-info/article/retinoscopy-101 [accessed on Feb 14, 2019]
https://www.allaboutvision.com/eye-exam/expect.htm [accessed on Feb 14, 2019]
https://www.lybrate.com/lab-test/retinoscopy [accessed on Feb 14, 2019]
https://www.northrangeeyecare.com/your-eye-health/eye-exams/common-tests/retinoscope/ [accessed on Feb 14, 2019]
https://www.slideshare.net/laxmieyeinstitute/retinoscopy-and-its-principles [accessed on Feb 14, 2019]
Additional Materials (17)
B&L Retinoscope
Bausch & Lomb Copeland Streak Retinoscope
Image by Janee
Retinoscopy of the eye (Ophthalmology)
Video by Tim Root/YouTube
Performing a Retinoscopy
An eye care professional performs retinoscopy to determine the child’s refractive error (eyeglass prescription).
Image by National Eye Institute
Determining Eyeglass Prescription
An eye care professional performs retinoscopy to determine the child’s refractive error (eyeglass prescription).
Image by National Eye Institute
Refractive Error Fact Sheet
Refractive errors occur when the shape of the eye prevents light from focusing directly on the retina. The length of the eyeball (longer or shorter), changes in the shape of the cornea, or aging of the lens can all cause refractive errors.
Document by National Eye Institute
Nearsightedness Fact Sheet
Nearsightedness, also known as myopia, is a common type of refractive error where close objects appear clearly, but distant objects appear blurry.
Document by National Eye Institute
Pediatric Eye Exam
An eye care professional conducts a pediatric eye exam on a child.
Image by National Eye Institute
Pediatric Eye Exam
An eye care professional performs retinoscopy to determine the child’s refractive error (eyeglass prescription).
Image by National Eye Institute
Retinoscopy
This woman was pictured in her doctor’s office, while undergoing an eye exam. Using an ophthalmoscope, the doctor was looking inside the interior of the patient’s right eyeball, in order to see if any intraocular damage had occurred, as a result of this patient's diabetic condition. Note the eye chart in the background, which is known as an E chart, or a tumbling E chart.
Image by CDC/ Amanda Mills
Retinoscopy
This woman was pictured in her doctor’s office, while undergoing an eye exam. Using an ophthalmoscope, the doctor was looking inside the interior of the patient’s left eyeball, in order to see if any intraocular damage had occurred, as a result of this patient's diabetic condition.
Image by CDC/ Amanda Mills
Retinoscopy
This woman was pictured in her doctor’s office, while undergoing an eye exam. Using an ophthalmoscope, the doctor was looking inside the interior of the patient’s left eyeball, in order to see if any intraocular damage had occurred, as a result of this patient's diabetic condition. Note the eye chart in the background, which is known as an E chart, or a tumbling E chart.
Image by CDC/ Amanda Mills
Eye exam
The woman pictured here, was undergoing an eye exam, whereupon, she was testing her visual acuity, by covering her left eye, and reading from a door-mounted eye chart, which used numbers as its symbols. Note that this eye chart was intended to be used with the patient standing at a distance of 10 feet from the chart.
Image by CDC/ Amanda Mills
Retinoscopy
The woman pictured here, was undergoing an eye exam, whereupon, she was testing her visual acuity, by covering her left eye, and reading from a door-mounted eye chart, which used numbers as its symbols. The clinician was pointing to each of the various numbers, and the patient was reciting the highlighted number. Note that this eye chart was intended to be used with the patient standing at a distance of 10 feet from the chart.
Image by CDC/ Amanda Mills
Retinoscopy
This seated female patient was in the process of receiving an eye examination, being conducted by a female physician, who was using a handheld ophthalmoscope, enabling her to see into the patient’s left eye.
Image by CDC/ Amanda Mills
Retinoscopy
This seated female patient was in the process of receiving an eye examination from a female physician, who was using a hand-held ophthalmoscope to see into her right eye.
Image by CDC/ Amanda Mills
Retinoscopy
This seated young female patient was in the process of receiving an eye examination from a male clinician, who was using a hand-held ophthalmoscope to see into her right eye.
Image by CDC/ Amanda Mills
Middle schoolers receive health screenings
A 52nd Aerospace Medicine Squadron optometrist, uses lenses to perform a retinoscopy on a Spangdahlem Middle School student during a school health screening on Spangdahlem Air Base, Germany, Nov. 7, 2014. The screenings are held once a year to assess the weight, height, eyesight and hearing of students. (U.S. Air Force photo by Staff Sgt. Christopher Ruano/Released)
Image by U.S. Air Force photo by Staff Sgt. Christopher Ruano/Released
B&L Retinoscope
Janee
4:43
Retinoscopy of the eye (Ophthalmology)
Tim Root/YouTube
Performing a Retinoscopy
National Eye Institute
Determining Eyeglass Prescription
National Eye Institute
Refractive Error Fact Sheet
National Eye Institute
Nearsightedness Fact Sheet
National Eye Institute
Pediatric Eye Exam
National Eye Institute
Pediatric Eye Exam
National Eye Institute
Retinoscopy
CDC/ Amanda Mills
Retinoscopy
CDC/ Amanda Mills
Retinoscopy
CDC/ Amanda Mills
Eye exam
CDC/ Amanda Mills
Retinoscopy
CDC/ Amanda Mills
Retinoscopy
CDC/ Amanda Mills
Retinoscopy
CDC/ Amanda Mills
Retinoscopy
CDC/ Amanda Mills
Middle schoolers receive health screenings
U.S. Air Force photo by Staff Sgt. Christopher Ruano/Released
Treatment
Green cone monochromacy to see plants
Image by Rii'jeg'fkep'c/Wikimedia
Green cone monochromacy to see plants
Green cone monochromacy to see plants
Image by Rii'jeg'fkep'c/Wikimedia
What's the Treatment for Color Blindness?
There’s no cure for color blindness that’s passed down in families, but most people find ways to adjust to it. Children with color blindness may need help with some classroom activities, and adults with color blindness may not be able to do certain jobs, like being a pilot or graphic designer. Keep in mind that most of the time, color blindness doesn’t cause serious problems.
If your color blindness is happening because of another health problem, your doctor will treat the condition that’s causing the problem. If you’re taking a medicine that causes color blindness, your doctor may adjust how much you take or suggest you switch to a different medicine.
If color blindness is causing problems with everyday tasks, there are devices and technology that can help, including:
Glasses and contacts. Special contact lenses and glasses may help people who are color blind tell the difference between colors.
Visual aids. You can use visual aids, apps, and other technology to help you live with color blindness. For example, you can use an app to take a photo with your phone or tablet and then tap on part of the photo to find out the color of that area.
Talk over your options with your eye doctor. Remember these tips:
Ask your doctor about visual aids and technology that can help you with everyday tasks
Encourage family members to get checked for color blindness, since it can run in families
Source: National Eye Institute (NEI)
Additional Materials (3)
The ColorAdd color identification system for colorblind people
The ColorAdd color identification system for colorblind people
Image by Maximilian Dörrbecker (Chumwa)
Do Those Glasses Really Fix Colorblindness?
Video by SciShow/YouTube
Is there a Cure for Color Blindness?
Video by Contact Lens King/YouTube
The ColorAdd color identification system for colorblind people
Send this HealthJournal to your friends or across your social medias.
Color Blindness
If you have color blindness, you'll see colors differently than others and will have difficulty seeing the difference between certain colors. It's usually genetic and is more common in men. Learn about genetic factors and how to adjust if you are color blind.