iodopsin

Iodopsin is a photosensitive pigment found in the cone cells of the vertebrate retina. It is crucial for vision in bright light and for color perception. Iodopsin is similar to rhodopsin, the pigment found in rod cells, but it is more unstable and plays a role in daylight vision.12

The structure of iodopsin, like other visual pigments, consists of a protein called opsin and a chromophore, which is a molecule derived from vitamin A called retinal. Specifically, iodopsin is a photopsin pigment that uses retinal. The opsin component of iodopsin differs from that of rhodopsin, allowing it to function optimally in brighter light conditions. The violet color of iodopsin comes from its Greek root "ioeidēs," meaning violet-colored.231