optokinetic nystagmus


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nystagmus

 [nis-tag´mus]
involuntary, rapid, rhythmic movement (horizontal, vertical, rotatory, or mixed, i.e., of two types) of the eyeball. adj., adj nystag´mic.
amaurotic nystagmus nystagmus in the blind or in those with defects of central vision.
amblyopic nystagmus nystagmus due to any lesion interfering with central vision.
aural nystagmus labyrinthine nystagmus.
caloric nystagmus rotatory nystagmus in response to caloric stimuli in the ear, seen during the caloric test.
Cheyne's nystagmus a peculiar rhythmical eye movement resembling Cheyne-Stokes respiration in rhythm.
congenital nystagmus (congenital hereditary nystagmus) nystagmus usually present at birth, usually horizontal and pendular, but occasionally jerky and pendular; the nystagmus may be caused by or associated with optic atrophy, coloboma, albinism, bilateral macular lesions, congenital cataract, severe astigmatism, and glaucoma.
dissociated nystagmus that in which the movements in the two eyes are dissimilar.
end-position nystagmus that occurring only at extremes of gaze.
fixation nystagmus that occurring only on gazing fixedly at an object.
gaze nystagmus nystagmus made apparent by looking to the right or to the left.
labyrinthine nystagmus vestibular nystagmus due to labyrinthine disturbance.
latent nystagmus that occurring only when one eye is covered.
lateral nystagmus involuntary horizontal movement of the eyes.
optokinetic nystagmus nystagmus induced by looking at objects moving across the visual field.
pendular nystagmus nystagmus in which the oscillations of the eyes have an equal rate, amplitude, direction, and type of movement.
positional nystagmus that which occurs, or is altered in form or intensity, on assumption of certain positions of the head.
retraction nystagmus (nystagmus retracto´rius) a spasmodic backward movement of the eyeball occurring on attempts to move the eye; a sign of midbrain disease.
rotatory nystagmus involuntary rotation of the eyes about the visual axis.
secondary nystagmus nystagmus occurring after the abrupt cessation of rotation of the head, caused by the labyrinthine fluid continuing to move.
spontaneous nystagmus that occurring without specific stimulation of the vestibular system.
vertical nystagmus involuntary up-and-down movement of the eyes.
vestibular nystagmus nystagmus due to disturbance of the labyrinth or of the vestibular nuclei; the movements are usually jerky.

op·to·ki·net·ic nys·tag·mus

nystagmus induced by looking at moving visual stimuli.

op·to·ki·net·ic nys·tag·mus

(op'tō-ki-net'ik nis-tag'mŭs)
Nystagmus induced by looking at moving visual stimuli.
References in periodicals archive ?
There was no significant difference between GI and GIII in the comparison of saccadic eye movements and optokinetic nystagmus tests, except for the slower movement velocity of the left eye in the group with dyslexia (Table 3).
In the comparison between GII and GIII in the saccadic eye movement tests compared to optokinetic nystagmus tests, there was no significant difference, except for the latency of the saccadic movement of the left eye, which had the longest latency in the group with learning disorder (Table 4).
(5) In a patient with MSA where a combination of olivopontocerebellar atrophy and striato-nigral degeneration was present, the typical impairments of eye movement characteristic of PD were evident, viz., abnormal eye movements, (6) in combination with a vertical optokinetic nystagmus. (7) However, smooth pursuit and saccadic movements in the vertical direction were only slightly affected.
A = Amplitude, L = Latency, VEP = Visual evoked potential, VOR=Vestibulo-ocular reflex, OKN = Optokinetic nystagmus, ?
(4) Post rotational nystagmus (optokinetic nystagmus) is very common in autism (sensory defensive but not sensory seeking) and is associated with gravitational insecurity ie fear of movement.