Physiologic Nystagmus (Paperback)

High Quality Content by WIKIPEDIA articles! High Quality Content by WIKIPEDIA articles! Physiologic nystagmus is a form of involuntary eye movement that is part of the vestibulo-ocular reflex (VOR). It is characterized by alternating smooth pursuit in one direction and saccadic movement in the other direction. Nystagmus can be caused by subsequent foveation of moving objects, pathology, sustained rotation or substance use. For example, if one fixates on a stripe of a rotating drum with alternating black and white, the gaze retreats to fixate on a new stripe as the drum moves. This is first a rotation with the same angular velocity, then returns in a saccade in the opposite direction. The process proceeds indefinitely. This is optokinetic nystagmus, and is a source for understanding the fixation reflex.