What triggers the Optokinetic reflex?
It is seen when an individual tracks (pursuit movement) a moving object with their eyes, which then moves out of the field of vision at which point their eye moves back to the position it was in (saccade movement) when it first saw the object. The reflex develops at about 6 months of age.
What is Optokinetic eye movement?
Optokinetic nystagmus is a rhythmic involuntary conjugate ocular movement in response to the movement of full visual field images, either rotation of an image before the subject, such as a drum with vertical black stripes on a white background, or rocking of a mirror back and forth in front of the patient’s eyes.
What is Optokinetic nystagmus test?
Optokinetic nystagmus (OKN) is a physiologic phenomenon produced by asking the patient to visually track a succession of moving stimuli. OKN eye movements involve two phases: the first is smooth pursuit eye movements in the direction of the moving target and the second is nystagmus in the contralateral direction.
What is end gaze nystagmus?
End-point nystagmus is the nystagmus associated with extreme positions of gaze. It is a fine jerk nystagmus with the fast phase being in the direction of the gaze. Optokinetic nystagmus describes the nystagmus that occurs when following a moving object (such as looking out of a train window).
What is a retinal slip?
Definition. Motion of the visual image on the surface of the retina. Slip of the visual image across large portions of the retina is the stimulus that stimulates optokinetic eye movements, and also the stimulus that produces the adaptation (improvement) of the optokinetic system.
What is the purpose of Optokinetic nystagmus?
Purpose of the optokinetic nystagmus test The optokinetic reflex allows the eyes to follow objects in motion while the head remains stationary. This function is performed within the central vestibular system.
What is normal nystagmus?
Nystagmus can be defined as a repetitive, involuntary, to-and-fro oscillation of the eyes. It may be physiological or pathological and may be congenital or acquired. It is a symptom, not a diagnosis. It is usually involuntary.
What is the function of the optokinetic reflex?
The optokinetic reflex is when a patient follows an object and there are both smooth and saccadic eye movements. It allows following an object out of the field of vision and the eye returning to the original position it was when viewing the object initially.
Which is an example of an optokinetic nystagmus?
Optokinetic nystagmus is a rhythmic involuntary conjugate ocular movement in response to the movement of full visual field images, either rotation of an image before the subject, such as a drum with vertical black stripes on a white background, or rocking of a mirror back and forth in front of the patient’s eyes.
Which is the horizontal optokinetic response for a random dot pattern?
Horizontal optokinetic nystagmus. Stare nystagmus for a random dot pattern moving from left to right. The optokinetic response is a combination of a slow-phase and fast-phase eye movements.
Is the pupillary light reflex an autonomic reflex?
In this article, we will cover a variety of reflexes involving the eye and their ophthalmologic considerations. The pupillary light reflex is an autonomic reflex that constricts the pupil in response to light, thereby adjusting the amount of light that reaches the retina.
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