- Nystagmus is a condition of involuntary (or voluntary, in rare cases) eye movement, acquired in infancy or later in life, that may result in reduced or limited vision. Due to the involuntary movement of the eye, it is often called “dancing eyes”.
- Rhythmic, oscillating motions of the eyes are called nystagmus. The to-and-fro motion is generally involuntary. Vertical nystagmus occurs much less frequently than horizontal nystagmus and is often, but not necessarily, a sign of serious brain damage. Nystagmus can be a normal physiological response or a result of a pathologic problem.