Nystagmus

Nystagmus is a biphasic (to and fro) ocular oscillation in which the two phases have approximately equal amplitudes. Sparked by significant advances in our knowledge of ocular movement physiology, the nystagmus literature has recently burgeoned. Serious contributions must be based upon quantitative eye movement recordings which, although required for the understanding of nystagmus mechanisms, are unavailable to most clinicians.* Fortunately, the common forms of nystagmus and other ocular oscillations may be recognized clinically with out the need for eye movement recording, and it is the clinical appearance which will be particularly emphasized in this review. A brief introduction to nomenclature is required.