A cataract is a clouding of the lens in your eye. It affects your vision. Cataracts are very common in older people. By age 80, more than half of all Americans either have a cataract or have had cataract surgery.

A cataract can occur in either or both eyes. It cannot spread from one eye to the other. Common symptoms are

• Blurry vision
• Colors that seem faded
• Glare - headlights, lamps or sunlight may seem too bright. You may also see a halo around lights.
• Not being able to see well at night
• Double vision
• Frequent prescription changes in your eye wear

Cataracts usually develop slowly. New glasses, brighter lighting, anti-glare sunglasses or magnifying lenses can help at first. Surgery is also an option. It involves removing the cloudy lens and replacing it with an artificial lens. Wearing sunglasses and a hat with a brim to block ultraviolet sunlight may help to delay cataracts.

What are cataracts?

A cataract is a cloudy area in the lens of your eye. Cataracts are very common as you get older. In fact, more than half of all Americans age 80 or older either have cataracts or have had surgery to get rid of cataracts.

At first, you may not notice that you have a cataract. But over time, cataracts can make your vision blurry, hazy, or less colorful. You may have trouble reading or doing other everyday activities.

The good news is that surgery can get rid of cataracts. Cataract surgery is safe and corrects vision problems caused by cataracts.

What are the types of cataracts?

Most cataracts are age-related — they happen because of normal changes in your eyes as you get older. But you can get cataracts for other reasons — for example, after an eye injury or after surgery for another eye problem (like glaucoma).

No matter what type of cataract you have, the treatment is always surgery.

Did you know?

• You can get cataracts in one eye or both eyes — but they can’t spread from one eye to the other
• By age 80, most people either have cataracts or have had cataract surgery
• Cataract surgery is one of the most common operations in the United States

What causes cataracts?

Most cataracts are caused by normal changes in your eyes as you get older.

When you’re young, the lens in your eye is clear. Around age 40, the proteins in the lens of your eye start to break down and clump together. This clump makes a cloudy area on your lens — or a cataract. Over time, the cataract gets more severe and clouds more of the lens.

What’s the latest research on cataracts?

Scientists are studying what causes cataracts and how we can find them earlier and treat them better. NEI also funds research on new treatment options.

As we age, our vision changes. Cataracts are one such common change. A cataract is a cloudy area in the lens of your eye. By age 80, most people either have cataracts or have had surgery to remove them.

Around age 40, the proteins in the lens of your eye start to break down and clump together. This clumping makes a cloudy area on your lens that gets worse over time.

At first, you may not have any symptoms. But eventually your vision becomes blurry and colors seem faded. You may also have trouble seeing at night.

Luckily, cataracts can be corrected with surgery. Cataract surgery is one of the most common operations in the U.S. Your doctor may recommend surgery if your cataracts start getting in the way of everyday activities like reading, driving, or watching TV.

During cataract surgery, the doctor removes the clouded lens and replaces it with a new, artificial lens. Surgery is very safe. Nine out of 10 people who get it can see better afterwards. But most people don’t need to rush into surgery. Talk with your health care provider if you’re having vision problems.

There are things you can do to delay cataracts. Wear sunglasses and a hat to block the sun. Quit smoking. Eat plenty of fruits and vegetables—especially dark, leafy greens like spinach and kale. And if you’re age 60 or older, get a dilated eye exam at least once every two years.

As life goes on, we all start to notice certain changes that are a natural part of aging. Maybe our joints aren’t as flexible as before, or our hearing just isn’t what it used to be. Our vision, too, may be less sharp than it once was.

One cause of impaired eyesight later in life is cataracts. A cataract is a clouding of the lens in the eye. People with cataracts may notice cloudy vision or halos around lights when driving at night. If left untreated, cataracts can greatly limit vision. In fact, some people with severe cataracts may only be able to tell the difference between light and dark.

Cataracts are common in older adults. About half of all Americans will either have cataracts or have had cataract surgery by the time they reach age 80.

“I don’t usually think of cataract as an eye disease. In most cases, it’s simply a normal aging change of the eye,” says Dr. Rachel Bishop, an ophthalmologist (eye doctor) at NIH. “Typically, cataracts don’t cause damage to the eye the way most eye diseases do.”

Early symptoms of cataract can be improved with eyeglasses, brighter lighting, anti-glare sunglasses or magnifying lenses. If these steps don’t help, surgery is the only effective option for treatment. Surgery involves removing the cloudy lens and replacing it with a plastic lens.

Cataract procedures are among the most common surgeries performed in the United States. Most patients recover in just a few weeks, and many have improved eyesight after a few days. Recent advances have allowed doctors to tailor new lenses to patients and help reduce the need for eyeglasses after surgery.

The decision to have cataract surgery is a personal one that should be made between you and your doctor. Some experts advise that cataracts be removed only when vision loss interferes with your everyday activities, such as driving, reading or watching TV.

The best way to prevent or delay cataracts is to protect your eyes from harmful ultraviolet rays from the sun. Try wearing sunglasses or a hat with a brim. Researchers also believe that good nutrition can help reduce the risk of age-related cataract. They recommend eating plenty of green leafy vegetables, fruits, nuts and other healthy foods. Also, don’t smoke, because smoking may speed cataract development.

To screen for early signs of eye disease, Bishop recommends that everyone have a dilated eye exam at age 40, even if your vision seems fine. Once you’re in your 60s, a dilated eye exam is usually advised every year.

“Some people think reduced vision is just an unavoidable part of normal aging,” says Bishop. “It isn’t. If you notice your vision isn’t as good as it used to be, you should see your eye doctor.” Since many serious eye diseases have no early warning signs, it’s also important to make regular eye exams part of your standard health care routine.

Cataract Symptoms

Check with an eye care professional if you have any of these symptoms. They may also be a sign of other eye problems:

• Cloudy or blurry vision.
• Colors seem faded.
• Glare—headlights, lamps or sunlight may appear too bright. A halo may appear around lights.
• Poor night vision.
• Double vision or multiple images in one eye. (This symptom may clear as the cataract gets larger.)
• Frequent prescription changes in your eyeglasses or contact lenses.

Not seeing clearly? Cataracts might be the problem.

Like a camera, your eyes rely on a lens—the clear part of the eye that helps to focus light, or an image, on the retina. A cataract is a clouding of the lens in the eye that affects vision. Most cataracts are related to aging. By age 80, more than half of all Americans either have a cataract or have had cataract surgery.

June marks National Cataract Awareness month. The National Eye Institute (NEI) has helpful resources on the condition, symptoms, and potential treatment options, which have been summarized below. For resources on cataracts from NEI, including an animation on what a cataract looks like, visit NEI's website.

What are the most common symptoms of a cataract?

• Cloudy or blurry vision.
• Colors may seem faded.
• Seeing a glare. Headlights, lamps, or sunlight may appear too bright. A halo may appear around lights.
• Poor night vision.
• Double vision or multiple images in one eye. (This symptom may clear as the cataract gets larger.)
• Frequent prescription changes in your eyeglasses or contact lenses.

These symptoms also can signal other eye problems. If you have any of these symptoms, be sure to check with your eye care professional.

Are there different types of cataracts?

Yes. Although most cataracts are related to aging, there are other types:

• Secondary cataract. Cataracts can form after surgery for other eye problems, such as glaucoma. Cataracts also can develop in people who have other health problems, such as diabetes. Cataracts are sometimes linked to steroid use.
• Traumatic cataract. Cataracts can develop after an eye injury, sometimes years later.
• Congenital cataract. Some babies are born with cataracts or develop them in childhood, often in both eyes. These cataracts may be so small that they do not affect vision. If they do, the lenses may need to be removed.
• Radiation cataract. Cataracts can develop after exposure to some types of radiation.

How is a cataract treated?

The symptoms of an early cataract may improve with new eyeglasses, brighter lighting, anti-glare sunglasses, or magnifying lenses. If these measures do not help, surgery is the only effective treatment. Surgery involves removing the cloudy lens and replacing it with an artificial lens.

What research is being done?

The National Eye Institute is conducting and supporting studies focusing on factors associated with the development of age-related cataracts. These studies include:

• The effect of sunlight exposure, which may be associated with an increased risk of cataracts.
• Vitamin supplements, which have shown varying results in delaying the progression of cataracts.
• Genetic studies, which show promise for better understanding cataract development.

A cataract is a cloudy area in the lens of your eye. Most cataracts are age-related — they happen because of normal changes in your eyes as you get older. But you can get cataracts for other reasons, too.

No matter what type of cataract you have, the treatment is always surgery.

There are 5 main types of cataracts.

Age-related cataract

As you age, a cataract can develop because of natural changes in the lens of your eye. This is called an age-related cataract, and it’s the most common type of cataract. Age-related cataracts may be more likely to form if you:

• Smoke
• Drink too much alcohol
• Have a family history of cataract
• Have diabetes
• Have had certain eye surgeries, like glaucoma surgery
• Take steroids (medicines used to treat a variety of health problems, like arthritis or allergies) for a long time

Traumatic cataract

Serious eye injuries can damage your lens and cause a cataract. The cataract could form quickly after the injury — or it could form many years later.

Radiation cataract

Certain types of radiation can cause cataracts. This includes ultraviolet (UV) rays from the sun and radiation treatment for cancer.

Pediatric cataract

Children can get cataracts, too. They can be born with cataracts (congenital cataracts), or develop them later on.

Cataracts in children are rare, and they’re usually genetic — they run in families. They can also happen because of serious complications during pregnancy or because of illnesses during childhood, like uveitis or tumors in the eye. Children can also get cataracts for the same reasons as adults — eye injuries, radiation, or steroid medications.

When pediatric cataracts are large enough to cause vision problems, they need immediate treatment. It’s important to treat these cataracts early on so your child doesn’t develop other vision problems, like amblyopia (lazy eye).

Other pediatric cataracts are so small that they won’t hurt your child’s vision. Your child’s doctor can monitor these smaller cataracts to make sure they don’t cause vision problems.

Secondary cataract (posterior capsule opacification)

After cataract surgery, some people may develop a condition called secondary cataract that makes their vision cloudy again. This condition is also called after-cataract or posterior capsule opacification. Secondary cataract is common, but it’s easy to fix with a laser treatment in your eye doctor’s office.

During cataract surgery, your doctor removes the lens from your eye and replaces it with a clear artificial lens. But over time, the thin membrane that holds your new lens in place can grow scar tissue and make your vision cloudy again.

Secondary cataracts aren’t actually cataracts, because they’re caused by cloudiness on the outside of your lens, not the inside — but the vision problems they cause are very similar. Up to half of all people who have had cataract surgery will develop a secondary cataract.

Treatment for secondary cataract is quick and painless. Your doctor will use a laser to make an opening in the membrane behind the artificial lens in your eye — this is called YAG laser capsulotomy. Most people will notice their vision is back to normal a few days after the procedure.

Your risk for cataracts goes up as you get older. You’re also at higher risk if you:

• Have certain health problems, like diabetes
• Smoke
• Drink too much alcohol
• Have a family history of cataracts
• Have had an eye injury, eye surgery, or radiation treatment on your upper body
• Have spent a lot of time in the sun
• Take steroids (medicines used to treat a variety of health problems, like arthritis and rashes)

If you’re worried you might be at risk for cataracts, talk with your doctor. Ask if there is anything you can do to lower your risk.

A cataract is a cloudy area in the lens of your eye. Cataracts can make your vision blurry, hazy, or less colorful.

Most cataracts are caused by natural changes in your eyes as you get older. The good news is that surgery can get rid of cataracts.

How does a cataract form?

Cataracts form when the proteins in the lens of your eye clump together, making your lens cloudy.

The lens of your eye is normally clear, allowing light to pass through. The lens helps focus the light on your retina (the light-sensitive layer of tissue in the back of your eye) so you can see things clearly, whether they’re up close or far away.

Your lens is mostly made of water and proteins. Normally, the proteins line up in a special way so that your lens is completely clear and light can pass through easily. If the proteins in your lens clump together, the lens gets cloudy.

Cataracts keep you from seeing clearly because light can’t pass through the clumps of proteins in your lens very easily. Over time, the clumps of proteins get bigger and thicker, making it harder for you to see. The lens may also develop a yellow or brown tint, which can change how you see colors.

What causes a cataract?

After age 40, the proteins in the lens of your eye naturally start to break down. Most cataracts happen because of these natural changes.

Doctors and researchers don’t know exactly what makes some people get cataracts, but they do know that there are things that can make cataracts form faster, including:

• Smoking
• Drinking too much alcohol
• Spending too much time in the sun without sunglasses

Some health problems and treatments can also make cataracts more likely, including:

• Diabetes
• A serious eye injury
• Eye surgery to treat glaucoma or another eye condition
• Taking steroids — medicines used to treat a variety of health problems, like arthritis or allergies — for a long time
• Getting radiation treatment for cancer or other diseases

You might not have any symptoms at first, when cataracts are mild. But as cataracts grow, they can cause changes in your vision. For example, you may notice that:

• Your vision is cloudy or blurry
• Colors look faded
• You can’t see well at night
• Lamps, sunlight, or headlights seem too bright
• You see a halo around lights
• You see double (this sometimes goes away as the cataract gets bigger)
• You have to change the prescription for your glasses often

These symptoms can be a sign of other eye problems, too. Be sure to talk to your eye doctor if you have any of these problems.

Over time, cataracts can lead to vision loss.

An eye doctor can check for cataracts as part of a dilated eye exam. The exam is simple and painless — your doctor will give you some eye drops to dilate (widen) your pupil and then check your eyes for cataracts and other eye problems.

What is a dilated eye exam?

A dilated eye exam is the best thing you can do for your eye health! It’s the only way to check for eye diseases early on, when they’re easier to treat — and before they cause vision loss.

The exam is simple and painless. Your eye doctor will check for vision problems that make it hard to see clearly, like being nearsighted or farsighted. Then your doctor will give you some eye drops to dilate (widen) your pupil and check for eye diseases.

Since many eye diseases have no symptoms or warning signs, you could have a problem and not know it. Even if you think your eyes are healthy, getting a dilated eye exam is the only way to know for sure.

How often do I need to get a dilated eye exam?

How often you need a dilated eye exam depends on your risk for eye disease. Talk to your doctor about what’s right for you.

Get a dilated eye exam every 1 to 2 years if you:

• Are over age 60
• Are African American and over age 40
• Have a family history of glaucoma

If you have diabetes or high blood pressure, ask your doctor how often you need an exam. Most people with diabetes or high blood pressure need to get a dilated eye exam at least once a year.

What happens during a dilated eye exam?

The exam includes:

• A visual acuity test to check how clearly you see. Your doctor will ask you to read letters that are up close and far away.
• A visual field test to check your peripheral (side) vision. Your doctor will test how well you can see objects off to the sides of your vision without moving your eyes.
• An eye muscle function test to check for problems with the muscles around your eyeballs. Your doctor will move an object around and ask you to follow it with your eyes.
• A pupil response test to check how light enters your eyes. Your doctor will shine a small flashlight into your eyes and check how your pupils react to the light.
• A tonometrytest to measure the pressure in your eyes. Your doctor will use a machine to blow a quick puff of air onto your eye, or gently touch your eye with a special tool. Don’t worry — it doesn’t hurt!
• Dilation to check for problems with the inner parts of your eye. Your doctor will give you some eye drops to dilate (widen) your pupil. This helps the doctor see inside your eye.

Depending on your needs, your doctor may include other tests too. Ask your doctor if you have questions.

How does dilation work?

Dilating your pupil lets more light into your eye — just like opening a door lets light into a dark room. Dilation helps your eye doctor check for many common eye problems, including diabetic retinopathy, glaucoma, and age-related macular degeneration (AMD).

What happens after a dilated eye exam?

For a few hours after a dilated eye exam, your vision may be blurry and you may be sensitive to light. Ask a friend or family member to drive you home from your appointment.

If your eye doctor finds refractive errors in your vision, you may get a prescription for eyeglasses or contact lenses to help you see more clearly.

Bring your sunglasses!

Your eyes may be sensitive to light for a few hours after your exam. Sunglasses can help, so bring them if you have them! Your eye doctor may also have disposable sunglasses they can give you.

If your eye doctor finds signs of an eye disease, you can talk about treatment options and decide what’s right for you.

If you’re seeing clearly and there are no signs of eye disease, you’re all set until your next exam. Make an appointment for your next dilated eye exam before you leave the office — that way, you won’t forget!

Surgery is the only way to get rid of a cataract, but you may not need to get surgery right away.

Home treatment. Early on, you may be able to make small changes to manage your cataracts. You can do things like:

• Use brighter lights at home or work
• Wear anti-glare sunglasses
• Use magnifying lenses for reading and other activities

New glasses or contacts. A new prescription for eyeglasses or contact lenses can help you see better with cataracts early on.

Surgery. Your doctor might suggest surgery if your cataracts start getting in the way of everyday activities like reading, driving, or watching TV. During cataract surgery, the doctor removes the clouded lens and replaces it with a new, artificial lens (also called an intraocular lens, or IOL). This surgery is very safe, and 9 out of 10 people who get it can see better afterwards.

Talk about your options with your doctor. Most people don’t need to rush into surgery. Waiting to have surgery usually won’t harm your eyes or make surgery more difficult later. Remember these tips:

• Tell your doctor if cataracts are getting in the way of your everyday activities
• See your doctor for regular check-ups
• Ask your doctor about the benefits and risks of cataract surgery
• Encourage family members to get checked for cataracts, since they can run in families

A cataract is a cloudy area in the lens of your eye that can make it hard to see clearly. Surgery is the only way to get rid of cataracts.

Who needs cataract surgery?

Your doctor will probably suggest cataract surgery if you have vision loss that gets in the way of everyday activities like reading, driving, or watching TV.

Sometimes, your doctor might recommend cataract surgery even if your cataracts aren’t the main cause of your vision problems. For example, cataracts might need to be removed so that your doctor can see the back of your eye. If you have another eye condition, like diabetic retinopathy or age-related macular degeneration (AMD), your doctor will need to see the back of your eye to help you manage it.

Cataracts are not a medical emergency, and you don’t need to rush to have surgery to remove them. Ask your doctor about the risks and benefits of cataract surgery to decide if it’s is right for you.

How do I prepare for cataract surgery?

At your doctor’s office before the day of the surgery, your doctor will do some tests to measure the size and shape of your eye. You may need to use some special eye drops before the surgery, and your doctor may tell you not to eat anything the night before your surgery.

You won’t be able to drive yourself home after the surgery, and you’ll need a friend or family member to make sure you get home safely — so be sure to bring someone with you.

If you have cataracts in both eyes, you’ll need to have surgery on each eye at a separate time, usually about 4 weeks apart.

What happens during cataract surgery?

During surgery, the doctor will remove the cloudy lens from your eye and replace it with an artificial lens (called an intraocular lens). The surgery lasts about 1 hour and is almost painless.

Usually, you will be awake during cataract surgery. You might notice lights or motion, but you won’t be able to see what your doctor is doing.

When you get this surgery, your doctor will:

• Put numbing drops into your eye to keep you from feeling anything
• Use tiny tools to cut into your eye, break up the lens, and take it out
• Place the new artificial lens in your eye

Right after surgery, you will need to rest in a recovery area outside the operating room for a little while. Before you go home, the medical team will check to make sure you don’t have any problems with your eye.

What happens after cataract surgery?

Your doctor will explain how to protect your eye after cataract surgery. They will give you eye drops to help your eye heal and you may need to wear a special eye shield or glasses. You may need to avoid some activities for a few weeks, like touching your eye, bending over, or lifting heavy things.

Your eye may feel a bit itchy or uncomfortable and sensitive to light and touch. After 1 or 2 days, your eye should feel better.

Call your doctor right away if you notice any of these problems after surgery:

• Vision loss
• Bad pain that won’t go away even if you take medicine for it
• Very red eyes
• Flashes of light or a lot of small dark spots or squiggly lines that float across your vision (floaters)

Most people are completely healed 8 weeks after their surgery. Your doctor will schedule checkups to make sure your eye is healing correctly.

Will my vision be normal after cataract surgery?

About 9 out of 10 people who get cataract surgery see better afterward, but your vision might be blurry at first while your eye recovers.

Some people notice that colors seem brighter after cataract surgery. This is because the artificial lens is clear, while your natural lens had a yellow or brown tint from the cataract.

Once your eye is completely healed, you might need a new prescription for glasses or contact lenses to see clearly.

What are the risks of cataract surgery?

Cataract surgery is one of the most common, safe, and effective types of surgery done in the United States. But like any surgery, there are risks, including:

• Swelling, bleeding, or infections
• Vision loss or double vision
• Unusual changes in eye pressure
• Retinal detachment
• Secondary cataract (posterior capsule opacity)

Your doctor can treat these problems if they are caught early. Be sure to go to all of your checkups, and call your doctor if you notice anything wrong with your eyes or your vision.

What is secondary cataract?

After cataract surgery, some people may develop a condition called secondary cataract, or posterior capsule opacification. Secondary cataracts aren’t actually cataracts, because they’re caused by cloudiness on the outside of your lens, not the inside — but they make your vision cloudy. Secondary cataracts can appear weeks, months, or even years after cataract surgery — but they are easy to fix with a laser treatment in the doctor’s office.

You can take steps to protect your eyes and delay cataracts.

• Wear sunglasses and a hat with a brim to block the sun.
• Quit smoking. If you’re ready to quit, call 1-800-QUIT-NOW (1-800-784-8669) for free support.
• Eat healthy. Eat plenty of fruits and vegetables — especially dark, leafy greens like spinach, kale, and collard greens.
• Get a dilated eye exam. If you’re age 60 or older, get a dilated eye exam at least once every 2 years.