Convergent evolution of dim light vision in owls and deep-diving whales.

Animals with enhanced dim-light sensitivity are at higher risk of light-induced retinal degeneration when exposed to bright light conditions. This trade-off is mediated by the rod photoreceptor sensory protein, rhodopsin (RHO), and its toxic vitamin A chromophore by-product, all-trans retinal. Rod arrestin (Arr-1) binds to RHO and promotes sequestration of excess all-trans retinal, which has recently been suggested as a protective mechanism against photoreceptor cell death.