Approach to Nystagmus

Abstract

The nystagmus is broadly classified in “jerk nystagmus” and “pendular nystagmus”. The jerk nystagmus is an involuntary biphasic rhythmic ocular oscillation with alternating slow drifts in one direction and corrective quick phase (the jerks) in the opposite direction. In contrast the pendular nystagmus has slow movements but no corrective jerks, instead sinusoidal to and fro oscillations as the pendulum of the clock. Jerk nystagmus is far more common than the pendular nystagmus, and typically (also throughout this book) the term “nystagmus” is used for jerk nystagmus unless specified as pendular nystagmus.