Nystagmus is a rhythmic and involuntary oscillatory movement of the eye globes that affects one or both eyes and can be caused by various causes.
Physiological nystagmus falls within the scope of normality; consists of a spontaneous eye movement evoked in a healthy subject as part of the vestibulo-ocular reflex, which stabilizes the images on the retina during a rapid movement of the head. It is evident, for example, during a visual chase, when an object is observed through the window of a car or train (a slow movement, a very rapid one follows, jerky).
