Visual Fixation: Spasm, Paralysis, Nystagmus, and the Visual Grasp Reflex

Disorders of visual fixation are manifested by involuntary fast eye movements that take the fovea off target (saccadic intrusions and oscillations). smooth eye movement oscillations that are enhanced by fixation (fixation nystagmus). spasm of fixation, paralysis of fixation. and the visual grasp reflex. Saccadic intrusions and oscillations have been previously reviewed (Sharpe and Fletcher. 1984) and presented at this Society. Disorders of visual fixation are superimposed upon miniature eye movements (under 0.25 degrees) that cannot be detected by inspection of the eyes: microsaccades, microdrift, and microtremor.