Nystagmus can be a sign of which dysfunction?

• A. Central cataracts
• B. Cerebellum or inner ear dysfunction
• C. Retinal detachment
• D. Optic neuritis

Answer: (B)

Nystagmus shows a disruption of the gaze-stabilizing system, most often from problems with the vestibulo-ocular pathway in the inner ear or with the cerebellum that tunes and coordinates eye movements. When the inner ear’s semicircular canals or the cerebellum aren’t functioning properly, the brain receives conflicted signals about head motion, so the eyes drift and then quickly correct in a rhythmic, fluttering way. This pattern is characteristic of vestibular or cerebellar dysfunction, which is why inner-ear or cerebellar problems are the best fit.

Central cataracts blur vision by scattering light through the lens, not by causing rhythmic eye movements. Retinal detachment and optic neuritis primarily affect vision clarity and color/contrast perception, often with pain or field loss, rather than producing nystagmus as a typical sign.