Moving Eyes, Nystagmus, Causes of Nystagmus, Types of Nystagmus

NYSTAGMUS
Nystagmus is a rhythmic oscillation of the eyes (moving eyes). It is a sign of disease of either the ocular or the vestibular system and its connections. Nystagmus impairs the visual ability of an individual.

There are ocular causes of Nystagmus (defect in eye, eye muscles), Central Causes of Nystagmus (nystagmus secondary to central vertigo, central vertigo results from damage to the vestibular nucleus of the brain stem. which has connections to the visual nucleus so any lesion of the vestibular nucleus may affect the visual nuclei) Peripheral causes of nystagmus ( Peripheral causes include diseases of the ear, the vestibular apparatus of the ear, inner ear infections, damage to semicircular canals etc)

Types of Nystagmus

There are two types of nystagmus:

Jerk Nystagmus

It is the usual nystagmus of neurological disease and has two components, fast and slow.

Horizontal or rotatory nystagmus
Horizontal or rotatory nystagmus may be due to the peripheral lesion (in the middle ear) or central lesion (in 8th nerve, brainstem cerebellum and their connections).

Vertical nystagmus
Vertical Nystagmus is only caused by the central lesion ( ie, by lesion inside the brain )

Pendular Nystagmus

Pendular nystagmus means to and fro movements, which are similar in amplitude and velocity.
It occurs in ocular diseases in which there is long-standing severe visual impairment