Eye reflex which alters the pupil's size in response to light intensity
Variation in the size of the pupil in bright (left) and dim (right) environments. In this case the pupil is 3 mm in diameter on the left, and 9 mm on the right
The pupillary light reflex (PLR) or photopupillary reflex is a reflex that controls the diameter of the pupil, in response to the intensity (luminance) of light that falls on the retinal ganglion cells of the retina in the back of the eye, thereby assisting in adaptation of vision to various levels of lightness/darkness. A greater intensity of light causes the pupil to constrict (miosis/myosis; thereby allowing less light in), whereas a lower intensity of light causes the pupil to dilate (mydriasis, expansion; thereby allowing more light in). Thus, the pupillary light reflex regulates the intensity of light entering the eye.[1] Light shone into one eye will cause both pupils to constrict.
The W-shaped pupil of the cuttlefish dilating when the lights are turned off
^Purves, Dale, George J. Augustine, David Fitzpatrick, William C. Hall, Anthony-Samuel LaMantia, James O. McNamara, and Leonard E. White (2008). Neuroscience. 4th ed. Sinauer Associates. pp. 290–1. ISBN 978-0-87893-697-7.{{cite book}}: CS1 maint: multiple names: authors list (link)
and 29 Related for: Pupillary light reflex information
The pupillarylightreflex (PLR) or photopupillary reflex is a reflex that controls the diameter of the pupil, in response to the intensity (luminance)...
Pupillaryreflex refers to one of the reflexes associated with pupillary function. These include the pupillarylightreflex and accommodation reflex. Although...
sphincter muscle PupillarylightreflexPupillaryreflex Pupillometry Pupilometer Ellis CJ (November 1981). "The pupillarylightreflex in normal subjects"...
unknown cause. Normally, as part of the pupillarylightreflex, the pupil dilates in the dark and constricts in the light to respectively improve vividity at...
the menace reflex, but will still have the pupillarylightreflex. Polioencephalomacia damages the visual cortex, impairing the menace reflex, but leaves...
reflexes, including the pupillarylightreflex and pupillary dark reflex. The pupillarylightreflex is an autonomic reflex that controls pupil diameter...
behavioral responses to acute changes in ambient light such as the pupillarylightreflex, the optokinetic reflex, and temporary changes to the circadian rhythm...
consistent. Automated assessment of the pupillarylightreflex has emerged as an objective means of measuring pupillary reactivity across a range of neurological...
light by controlling the size of the pupil. This is known as the pupillarylightreflex. The iris contains two groups of smooth muscles; a circular group...
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In biology, a reflex, or reflex action, is an involuntary, unplanned sequence or action and nearly instantaneous response to a stimulus. Reflexes are...
pupillometers may also be able to characterize pupillarylightreflex. Some instruments for measuring pupillary distance (PD) are often, but incorrectly, referred...
transient and sustained signaling of the pupillarylightreflex (PLR). Transient PLR occurs at dim to moderate light intensities and is a result of phototransduction...
the foot. Pupillary accommodation reflex — a reduction of pupil size in response to an object coming close to the eye. Pupillarylightreflex — a reduction...
regardless of which eye the light is directed at. This indicates an intact direct and consensual pupillarylightreflex. When the test is performed in...
PupillaryLightReflex (46" video). The University of Utah. May 2020. The swinging flashlight test is used to test for a relative afferent pupillary defect...
variety of photic responses, including pupillarylightreflex, and synchronization of the biological clock to daily light-dark cycles. He also described the...
end of the cerebral aqueduct. It is important in the bilateral pupillarylightreflex.[citation needed] It constitutes part of the epithalamus. Its fibers...
visual functions, independent of visual perception, including the pupillarylightreflex and circadian photoentrainment. This article describes the human...
effect circadian adjustment and to the pretectal area to control the pupillarylightreflex. Complex eyes distinguish shapes and colours. The visual fields...
Whytt explains that the pupillarylightreflex is the contractions and re-sizing of the pupil in different intensities of light. If the eye was incapable...
has shown the necessary use of an opaque eyecup as pupillarylightreflex is affected by ambiant light. It is important to mention that certain pupillometers...
Miles JH, Takahashi N, Yao G (November 2009). "Abnormal transient pupillarylightreflex in individuals with autism spectrum disorders". Journal of Autism...
day to avoid pain or discomfort of the eyes. The pupillarylightreflex caused by adjustment to light takes around five minutes in people with healthy...
cornea. Damage to the short ciliary nerve may result in loss of the pupillarylightreflex, or mydriasis. The short ciliary nerves are branches of the ciliary...
needed] In humans, it functions to constrict the pupil in bright light (pupillarylightreflex) or during accommodation.[citation needed] In lower animals...
light-sensing cell, the photosensitive ganglion cell, is important for entrainment of circadian rhythms and reflexive responses such as the pupillary...
eyes of elasmobranchs (skates, sharks and rays). It can undergo pupillarylightreflex to such an extent that the eye is essentially shut off. It is sometimes...
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