Editing Vestibular system (section)

===Vestibulo-ocular reflex (VOR)===
{{Main|Vestibulo-ocular reflex}}
[[Image:Simple vestibulo-ocular reflex.PNG|thumb|300px|The vestibulo-ocular reflex. A rotation of the head is detected, which triggers an inhibitory signal to the [[extraocular muscles]] on one side and an excitatory signal to the muscles on the other side. The result is a compensatory movement of the eyes.]]

The '''vestibular-ocular reflex''' ('''VOR''') is a [[reflex]] [[Eye movement (sensory)|eye movement]] that stabilizes images on the [[retina]] during head movement by producing an eye movement in the direction opposite to head movement, thus preserving the image on the center of the visual field. For example, when the head moves to the right, the eyes move to the left, and vice versa. Since slight head movements are present all the time, the VOR is very important for stabilizing vision: patients whose VOR is impaired find it difficult to read because they cannot stabilize the eyes during small head tremors. The VOR reflex does not depend on visual input and works even in total darkness or when the eyes are closed.

This reflex, combined with the push-pull principle described above, forms the physiological basis of the ''Rapid head impulse test'' or ''Halmagyi-Curthoys-test'', in which the head is rapidly and forcefully moved to the side while observing whether the eyes keep looking in the same direction.<ref>{{Cite web|url=https://collections.lib.utah.edu/ark:/87278/s6546h55|title=Vestibular neuritis with and head impulse test and unidirectional nystagmus|last=Gold|first=Daniel|website=Neuro-Ophthalmology Virtual Education Library (NOVEL): Daniel Gold Collection. Spencer S. Eccles Health Sciences Library.|access-date=20 November 2019}}</ref>