Visual pigments are the light-absorbing molecules that mediate vision. They consist of an apoprotein, opsin, covalently linked to cis-retinal. May increase spectral sensitivity in dim light. Monomer. Homodimer. Homotetramer. Expressed in retina (at protein level) (PubMed:30948514). Expressed in cone photoreceptor cells (at protein level) (PubMed:11055434). Expressed in the retinal outer nuclear layer and the inner nuclear layer at postnatal day 10. N-glycosylated (PubMed:30948514). O-glycosylated (PubMed:30948514). Phosphorylated on some or all of the serine and threonine residues present in the C-terminal region. Belongs to the G-protein coupled receptor 1 family. Opsin subfamily.