Nystagmus is a condition in which the eyes move involuntarily, typically in a rhythmic pattern.

Nystagmus can be categorized in different ways, including based on age at onset, type of eye movement, or specific cause.

There are 2 major categories of nystagmus related to when the disease occurs. Congenital nystagmus is present shortly after birth. Acquired nystagmus begins after 6 months of life. Congenital motor nystagmus is the most common type of congenital nystagmus. This usually occurs by itself, is not associated with any other congenital abnormalities, and does not go away but can lessen with time. Other causes of congenital nystagmus include developmental abnormalities in the eye structures, such as the cornea, lens, retina, and optic nerve, or abnormalities in the visual pathways in the brain.