Holmes-Adie syndrome, also known as Adie Syndrome, is a neurological disorder that affects the pupil of the eye and the autonomic nervous system (which controls things that happen automatically in the body, such as heart rate, blood pressure, and digestion).

Holmes-Adie syndrome involves a pupil in one eye that is larger than the other and constricts slowly in bright light as well as the absence of deep tendon reflexes usually in the Achilles tendon (back of calf through heel bone). Both eye and tendon reflex issues may start on one side of the body before progressing to the other side.

Its direct cause is unknown but may involve an infection and damage to nerve cells in the ciliary ganglion, an area of the brain that controls eye movement, and the dorsal root ganglion, an area of the spinal cord that is involved in the autonomic nervous system. People with the syndrome also may sweat excessively; the combination of symptoms is sometimes known as Ross syndrome.

Holmes-Adie syndrome is not life threatening or disabling, but the loss of deep tendon reflexes is permanent. Treatment, if any, may involve reading glasses and eye drops. Surgery to sever the involved sympathetic nerve may reduce excessive sweating.