Visual pigments are the light-absorbing molecules that mediate vision. They consist of an apoprotein, opsin, covalently linked to cis-retinal. Some or all of the Ser/Thr residues present in the C-terminal part may be phosphorylated. Opsin Rh2 is the predominant opsin expressed in the dorsal ocelli. Belongs to the G-protein coupled receptor 1 family. Opsin subfamily.