Rhodopsin, also known as visual purple,'s a pigment of the retina that's responsible for both the formation of the photoreceptor cells and the first events in the perception of light. Rhodopsins belong to the G-protein coupled receptor family and are extremely sensitive to light, enabling vision in low-light conditions. Exposed to light, the pigment immediately photobleaches, and it takes about 30 minutes to regenerate fully in humans. Structure Rhodopsin consists of the protein moiety opsin an… (More on Rhodopsin)