optokinetic nystagmus

This is optokinetic nystagmus, and is a source for understanding the fixation reflex.

Optokinetic nystagmus (OKN) is nystagmus that occurs in response to a rotation movement.

When factitious blindness or malingering is suspected, check for optokinetic nystagmus to determine whether there is an intact visual pathway.

Eliciting optokinetic nystagmus (OKN)

In contrast, binocular optokinetic nystagmus (OKN), for which a subcortical pathway has often been thought adequate, showed a marked asymmetry.

FIG. 3 The asymmetry of optokinetic nystagmus for subject P.P. tested at age 9 months (5 months after R hemispherectomy).

The patient may or may not have any or all of the following associated conditions: Oblique muscle dysfunction, vertical incomitance, dissociated vertical deviation, asymmetric optokinetic nystagmus, torticollis.

A simple but less-used technique is checking oculomotor responses with an optokinetic nystagmus drum, where the subject is placed inside the drum and surrounded by rotating black and white stripes.

Initiated cortically by the frontal eye fields (FEF), or subcortically by the superior colliculus, saccades serve as a mechanism for fixation, rapid eye movement, and the fast phase of optokinetic nystagmus.

Ji, J.T.T., So, R.H.Y. and Cheung, R.T.F. (2009) Isolating the effects of vection and optokinetic nystagmus on visually induced motion sickness during exposure to optokinetic stimuli.

In addition to its role in maintaining smooth pursuit, the protectum is activated during the optokinetic nystagmus in which the eye returns to a central, forward-facing position after an object it was following passes out of the field of vision.