Photoreceptor contributions to the human pupil light reflex
Pablo A. Barrionuevo, Luis Issolio, Constanza Tripolone
Abstract
The pupil reacts to the amount of light reaching the eye. It reduces its size when the light is high and dilates at low light levels to allow the entrance of more photons. This behavior is called pupil light reflex (PLR). Recent investigations in humans were conducted to understand how the photoreceptor signals are combined to drive the pupil light reflex. This review is about the physiological processes that govern the pupil in humans. In particular, how cone-opsins, rhodopsin, and melanopsin photoreception contribute to governing the PLR. We also summarize investigations on the assessment of the PLR in clinical settings.
Topics & Concepts
MelanopsinPupilPupillary light reflexReflexNeurosciencePupil sizeRhodopsinIntrinsically photosensitive retinal ganglion cellsOpsinOpticsPhotopigmentPsychologyOptometryPhysicsRetinaBiologyOphthalmologyMedicineRetinalRetinal ganglion cellCircadian rhythm and melatoninOlfactory and Sensory Function StudiesPhotoreceptor and optogenetics research