May also be called: dancing eyes, rapid eye movements, involuntary eye movements

Nystagmus (say: ni-STAG-mus) is fast, uncontrollable eye movements.

More to Know

The brain and inner ear are involved with the normal function of eye movements. When these areas are not functioning normally, it can cause the eyes to move involuntarily. With nystagmus, the eyes may move from side to side, up and down, or in a circular pattern, and one or both eyes may be affected.

There are many types and causes of nystagmus. It can be present at birth (congenital nystagmus or infantile nystagmus syndrome) or develop later in life (acquired nystagmus). Congenital nystagmus is often mild but some kids may need corrective lenses for vision problems.

Acquired nystagmus can be caused by a reaction to certain drugs, medications, or alcohol. In most cases, acquired nystagmus goes away after the cause has been treated. In rare cases, it can be caused by a serious medical condition such as a stroke, cataracts, an inner ear disorder, or a head injury.

Brief periods of nystagmus are considered a normal reflex, like when there are sudden changes in position (for example, after a roller coaster ride or after spinning).

Keep in Mind

Congenital nystagmus may affect eyesight, but vision can be improved by glasses, contact lenses, or surgery. Discuss these and other potential treatment options with your doctor. Most cases of acquired nystagmus are treated by dealing with the underlying cause. Be sure to talk to your doctor if you are concerned about nystagmus.

All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.