Alexander's law refers to gaze-evoked nystagmus that occurs after an acute unilateral vestibular loss.
It was first described in 1912 and has three elements to explain how the vestibulo-ocular reflex responds to an acute vestibular insult.
The first element says that spontaneous nystagmus after an acute vestibular impairment has the fast phase directed toward the healthy ear.
The third element says that spontaneous nystagmus with central gaze is augmented when vision is denied.
The nystagmus becomes more intense when the patient looks in the quick-phase than in the slow-phase direction.