For vision to be effective, the retinal image must be stationary. This can be achieved only by maintaining the position of the eyes relative to the earth and using this as a stable platform for following a moving object. The vestibular system plays a critical part in this, mainly through complex and incompletely understood connections between the vestibular apparatus and the musculature of the eyes. Rotation of the head in any direction is detected by the semicircular canals, and a velocity signal is then passed via the vestibular nuclei to the somatic and extraocular muscles. In the case of the ...(100 of 37287 words)