Search results
Results from the WOW.Com Content Network
The pupillary light reflex (PLR) or photopupillary reflex is a reflex that controls the diameter of the pupil, in response to the intensity 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.
In humans the ipRGCs contribute to non-image-forming functions like circadian rhythms, behavior and pupillary light reflex. [14] Peak spectral sensitivity of the receptor is between 460 and 482 nm. [14] However, they may also contribute to a rudimentary visual pathway enabling conscious sight and brightness detection. [14]
[3] [2] It contributes the autonomic, parasympathetic component to the oculomotor nerve (CN III), [4] ultimately providing innervation to the iris sphincter muscle and ciliary muscle to mediate the pupillary light reflex and accommodation, respectively. [2] [3] The Edinger–Westphal nucleus has two parts.
The ability of the rodless, coneless mice to retain a pupillary light reflex was suggestive of an additional photoreceptor cell. [11] In the 1980s, research in rod- and cone-deficient rats showed regulation of dopamine in the retina, a known neuromodulator for light adaptation and photoentrainment. [3]
The visual system also has several non-image forming visual functions, independent of visual perception, including the pupillary light reflex and circadian photoentrainment. This article describes the human visual system, which is representative of mammalian vision, and to a lesser extent the vertebrate visual system.
Light from a single point of a distant object and light from a single point of a near object being brought to a focus. The accommodation reflex (or accommodation-convergence reflex) is a reflex action of the eye, in response to focusing on a near object, then looking at a distant object (and vice versa), comprising coordinated changes in vergence, lens shape (accommodation) and pupil size.
Although the pupillary response, in which the pupil dilates or constricts due to light is not usually called a "reflex", it is still usually considered a part of this topic. Adjustment to close-range vision is known as "the near response", while relaxation of the ciliary muscle to view distant objects is known as the "far response".
The pupil constricts when the iris sphincter muscle is stimulated and contracts. In humans, it functions to constrict the pupil in bright light (pupillary light reflex) or during accommodation. [citation needed] In lower animals, the muscle cells themselves are photosensitive causing iris action without brain input. [5]