obsolete nystagmus, voluntary (obsolete MONDO:0044246)
OBSOLETE. Voluntary nystagmus is a rapid to-and-fro synchronous movement of the eyes that is initiated and maintained by conscious effort. Voluntary nystagmus has a frequency of 10-25 Hz, with an amplitude of up to 6 degrees, and can be maintained for up to 35 seconds. It usually has its first appearance between ages 8 to 15 years. It can be produced in both light and darkness, without fixation, at all eye positions, and even with closed eyes. It is accompanied by oscillopsia with visual blurring (summary by {1:Aschoff et al., 1976}).