n. rapid involuntary eye movement, usually lateral
the GNU version of the Collaborative International Dictionary of English
n. A rapid involuntary oscillation of the eyeballs.
The Century Dictionary and Cyclopedia
n. In medicine, involuntary lateral oscillatory (sometimes rotatory, rarely vertical) motion of the eyes.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. involuntary movements of the eyeballs; its presence or absence is used to diagnose a variety of neurological and visual disorders
Word Usage
"There ` s also a test called nystagmus, in which an officer either a pen or his finger and actually tests the nystagmus, which is a natural twitching of somebody ` s eyes in response to a finger that ` s being moved from left to right."