To investigate the relation of the directional organization of the accessory optic system (AOS) to that of its principal behavioral output, optokinetic nystagmus (OKN), we measured the eye velocity during OKN in response to 14 directions of stimulus motion, including horizontal, vertical, cyclorotational (rotations about the optic axis), and intermediate directions in both neonatal and older ch...

Two exposure sessions consisted of 5 minutes in the optokinetic drum rotating clockwise at 35 degrees per second (slightly greater than the 5 r.p.m. used in previous experiments). Subjects viewed the drum with their spectacles or contact lenses on for one session, followed by a 20 minute rest period, then viewed the same optokinetic stimulation without their spectacles or contact lenses. Six su...

Nystagmus is a periodic, involuntary eye condition. It is characterized by the smooth pursuit of the eye away from the target location followed by a quick saccade back to the target location. Nystagmus is also called “dancing eyes” as the eye movements appear pendular or jerky to an observer. Everyone has nystagmus. Trying to fixate on objects far in your periphery will produce nystagmus-like m...

To ensure high acuity vision, eye movements have to be controlled with astonishing precision by the oculomotor system. Many human diseases can lead to abnormal eye movements, typically of the involuntary oscillatory eye movements type called nystagmus. Such nystagmus can be congenital (infantile) or acquired later in life. Although the resulting eye movements are well characterized, there is on...

Eye movement disorders may be considered in two categories: those that cause incomplete eye movements (ophthalmoparesis) and those that cause excessive eye movements (saccadic intrusions and nystagmus). Central to an understanding and correct diagnosis of abnormal eye movements is the evaluation of ocular alignment, ocular motility, and each functional class of eye movements: optokinetic, vesti...

BACKGROUND/AIMS Abnormalities in the saccadic main sequence are an important finding and may indicate pathology of the ocular motor periphery or central neurological disorders. In young or uncooperative patients it can be difficult eliciting a sufficient number of saccades to measure the main sequence. It is often assumed that the quick phases of optokinetic nystagmus (OKN) are identical to sac...

We investigated the development of oculomotor activity in zebrafish embryos and larvae of ages 48-96 hrs postfertilization (hpf). The optokinetic response (OKR: smooth tracking movements evoked by a rotating striped drum) improved steadily after its onset at 73 hpf, and by 96 hpf had a achieved a gain (eye velocity/drum velocity) of 0.9, comparable to adult performance. Reset movements (the fas...

The nucleus of the basal optic root of the accessory optic system in pigeons is involved in generating optokinetic nystagmus, which stabilizes object images on the retina by compensatory eye movements. Previous studies have indicated that basal optic neurons are selective for the direction and velocity of motion. The present study shows that these optokinetic cells also respond to stationary st...