nystagmus

Nystagmus is a condition of involuntary (or voluntary, in some cases) eye movement. People can be born with it but more commonly acquire it in infancy or later in life. In many cases it may result in reduced or limited vision.

Key facts

Medical condition (new).name: Nystagmus
Medical condition (new).synonyms: Dancing eyes, Instabilitas oculorum
Medical condition (new).image: Optokinetic nystagmus.gif
Medical condition (new).caption: Horizontal optokinetic nystagmus, a normal (physiological) form of nystagmus
Medical condition (new).field: Neurology, ophthalmology, optometry

via Wikipedia infobox

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Encyclopedic overview

20 sections

Contents

Causes
Early-onset nystagmus
Acquired nystagmus
General diseases and conditions
Toxicity or intoxication, metabolic disorders and combination
Thiamine deficiency
Central nervous system (CNS) diseases and disorders
Other causes
Diagnosis
Pathological nystagmus
Variations
Physiological nystagmus
Variations
Treatment
Epidemiology
Law enforcement
Media
See also
References
External links

In normal eyesight, while the head rotates about an axis, distant visual images are sustained by rotating eyes in the opposite direction of the respective axis. The semicircular canals in the vestibule of the ear sense angular acceleration, and send signals to the nuclei for eye movement in the brain. From here, a signal is relayed to the extraocular muscles to allow one's gaze to fix on an object as the head moves. Nystagmus occurs when the semicircular canals are stimulated (e.g., by means of the caloric test, or by disease) while the head is stationary. The direction of ocular movement is related to the semicircular canal that is being stimulated.

Excerpted from Wikipedia’s “nystagmus” article, available under the CC BY-SA 4.0 licence.