Visionrehab

Definition
Nystagmus is defined as involuntary, rhythmical, repeated oscillations of one or both eyes, in any or all directions of view. The movements may be of equal speed in each direction, or one direction may be faster than the other. Movements may be left and right, up and down, diagonal, or circular.

Causes
Nystagmus may be found at birth, may be induced by trauma to the brain such as a stroke, or can be associated with other neurological disorders.  It is also the result of various forms of albinism.

Effect on Vision The movement of the eyes minimizes the ability to focus the eyes on one point, also called fixation. This constant movement causes the vision to be less than optimum. Visual acuity in persons with nystagmus can commonly range from 20/30 to 20/400. Most individuals with nystagmus do not see movement to the world as one might expect. However, in some acquired forms of nystagmus, the movement is visible and is called oscillopsia. This movement can cause dizziness and nausea.

Treatments
There are no treatments for nystagmus currently. Adaptive measures should be taken to enhance functional vision. This includes obtaining the best optical correction, and evaluating the benefits of low vision devices.

Links

• American Nystagmus Network (ANN)
• British Nystagmus Network