May play a role in rpe physiology either by detecting light directly or by monitoring the concentration of retinoids or other photoreceptor-derived compounds. Found only in the eye, where it is localized to the retinal pigment epithelium (RPE). In the RPE, it is localized to the microvilli that surround the photoreceptor outer segments. Belongs to the G-protein coupled receptor 1 family. Opsin subfamily.