Spontaneous Nystagmus
Ask the patient to fixate on a stationary target in neutral gaze position with best corrected vision (glasses or contact lenses in place). Observe for nystagmus or rhythmic refixation eye movements. Repeat under Fresnel lenses to observe effect of target fixation.
(+) Test: Horizontal direction fixed - Labyrinth, VIII cranial nerve
Direction changing, pure rotational, or pure vertical - brain stem, cerebellum, and cerebrum
