Voluntary nystagmus: new findings and clinical implications.

Horizontal eye position was monitored during a variety of tracking tasks in three normal subjects capable of producing voluntary nystagmus. New findings included ability to superimpose voluntary nystagmus saccades on smooth movements during tracking of a target moving with constant acceleration, brief persistence of voluntary nystagmus, and transient occurrence of voluntary nystagmus, and transient occurrence of voluntary nystagmus-like movements and oscillopsia following an intense period of voluntary nystagmus-like movements and oscillopsia during marked convergence. Clinical implications of these new findings are discussed.