Search Result for "nystagmus": 
Wordnet 3.0

NOUN (1)

1. involuntary movements of the eyeballs; its presence or absence is used to diagnose a variety of neurological and visual disorders; 



The Collaborative International Dictionary of English v.0.48:

Nystagmus \Nys*tag"mus\, n. [NL., fr. Gr. ? drowsiness, fr. ? to
   nod in sleep, to slumber.] (Med.)
   A rapid involuntary oscillation of the eyeballs.
   [1913 Webster]


WordNet (r) 3.0 (2006):

nystagmus
    n 1: involuntary movements of the eyeballs; its presence or
         absence is used to diagnose a variety of neurological and
         visual disorders