iodopsin /ī′ōdop″sin/ [Gk, ioeides + optikos, vision] , a photosensitive chemical in the cones of the retina that reacts in association with other chemicals and plays a part in color vision. Iodopsin is more stable when exposed to bright light than rhodopsin, which is found in the rods of the retina. Color vision, a synthesis of red, green, and blue light, is induced by changes within the pigments of different types of cones during a photochemical process in which coded nerve impulses are sent to the brain. Research on the exact role of iodopsin in color vision, which is still unknown, is ongoing.
