The optokinetic response is a combination of a slow-phase and fast-phase
eye movement
Eye movement includes the voluntary or involuntary movement of the eyes. Eye movements are used by a number of organisms (e.g. primates, rodents, flies, birds, fish, cats, crabs, octopus) to fixate, inspect and track visual objects of interest ...
s. It is seen when an individual tracks (pursuit movement) a moving object with their eyes, which then moves out of the field of vision, a point at which their eyes move back to the initial position (saccade movement) when they first saw the object. The reflex develops at about 6 months of age.
Optokinetic nystagmus/response (OKN/R) is
nystagmus
Nystagmus is a condition of involuntary (or voluntary, in some cases) eye movement. Infants can be born with it but more commonly acquire it in infancy or later in life. In many cases it may result in reduced or limited vision. Due to the invol ...
that occurs in response to a visual stimulus on the
retina
The retina (from la, rete "net") is the innermost, light-sensitive layer of tissue of the eye of most vertebrates and some molluscs. The optics of the eye create a focused two-dimensional image of the visual world on the retina, which the ...
.
It is present in normally developed patients. The optokinetic response allows the eye to follow objects in motion when the head remains stationary (e.g., observing individual telephone poles on the side of the road as one travels by them in a car, or observing stationary objects while walking past them).
Diagnosis
Eliciting optokinetic nystagmus
With normal vision, an OKN response develops in infants and remains through adulthood. The OKN response consists of initial slow phases in the direction of the stimulus (smooth pursuits), followed by fast, corrective phases (return saccade).
Presence of an OKN response in the temporal to nasal direction indicates an intact visual pathway.
Another effective method is to hold a mirror in front of the patient and slowly rotate the mirror to either side of the patient. The patient with an intact visual pathway will maintain eye contact with themselves. This compelling optokinetic stimulus forces reflex slow eye movements.
Stereopsis development
This is particularly helpful in infantile strabismus to determine if motion stereopsis development is present or not.
Nasal to temporal motion tracking can be trained in infantile strabismus allowing for eye alignment (Baxtrom and Clopton, 2019) and may be associated with the Accessory Optic System for eye control.
See also
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Eye movement
Eye movement includes the voluntary or involuntary movement of the eyes. Eye movements are used by a number of organisms (e.g. primates, rodents, flies, birds, fish, cats, crabs, octopus) to fixate, inspect and track visual objects of interest ...
*
Nystagmus
Nystagmus is a condition of involuntary (or voluntary, in some cases) eye movement. Infants can be born with it but more commonly acquire it in infancy or later in life. In many cases it may result in reduced or limited vision. Due to the invol ...
*
Reflex
In biology, a reflex, or reflex action, is an involuntary, unplanned sequence or action and nearly instantaneous response to a stimulus.
Reflexes are found with varying levels of complexity in organisms with a nervous system. A reflex occurs ...
*
Saccadic masking
Saccadic masking, also known as (visual) saccadic suppression, is the phenomenon in visual perception where the brain selectively blocks visual processing during eye movements in such a way that neither the motion of the eye (and subsequent motion ...
References
External links
Optokinetic nystagmus testing
{{DEFAULTSORT:Optokinetic Reflex
Visual system
Vision
Articles containing video clips