photoreception

pho·to·re·cep·tion

noun \-ri-ˈsep-shən\

Definition of PHOTORECEPTION

: perception of waves in the range of visible light; specifically : vision

— pho·to·re·cep·tive \-ˈsep-tiv\ adjective

First Known Use of PHOTORECEPTION

1902

pho·to·re·cep·tion

noun \-ri-ˈsep-shən\   (Medical Dictionary)

Medical Definition of PHOTORECEPTION

: perception of waves in the range of visible light; specifically : vision 1

—pho·to·re·cep·tive \-ˈsep-tiv\ (audio pronunciation) adjective

photoreception

noun    (Concise Encyclopedia)

Biological responses to stimulation by light, most often referring to the mechanism of vision. In one-celled organisms such as the amoeba, the whole cell may be sensitive to light. Earthworms have photoreceptive cells scattered over their bodies to help orient themselves by comparison of light intensities in different directions. Most animals have localized photoreceptors of varying complexity. In humans, photoreception relies on the chemical response of a light-sensitive pigment, rhodopsin, in photoreceptor cells in the retina of the eye. Stimulation of those cells results in a stimulus being conducted toward the nervous system. Humans, like other vertebrates, have two types of photosensitive cells, rod cells and cone cells. Rod cells are responsible for vision when there is little light; cone cells mediate daylight vision and colour. Photoreception also refers to photosynthesis in plants. See also sense.