photopsin

Photopsins are proteins found in the photoreceptor cells of the eye, specifically in the cones, which are responsible for color vision. These proteins, along with a light-absorbing molecule called a chromophore (typically retinal), form visual pigments. When light strikes the chromophore, it changes shape, triggering a cascade of events that ultimately leads to an electrical signal sent to the brain. Humans have three types of photopsins, each sensitive to different wavelengths of light: blue, green, and red. The brain interprets the combined signals from these different cone types to perceive a wide range of colors.1234