what is rhodopsin
Medical Definition of RHODOPSIN. : a red photosensitive pigment in the retinal rods of marine fishes and most higher vertebrates that is important in vision in dim light, is quickly bleached by light to a mixture of opsin and retinal, and is regenerated in the darkâcalled also visual purple. a red photosensitive pigment in the retinal rods of the eye of most vertebrates that is important in vision in dim light âcalled also visual purple. ADVERTISEMENT.