Since scotopic vision is mainly dependent on rod and RBC function, and defects in rod or RBC function or survival result in night blindness in animal models, it is likely that some of the genes we have identified in the developing and adult Bhlhe23−/− retina will be implicated in patients with electronegative scotopic ERGs from inherited causes of night blindness. The gene discussed is BHLHE23; the disease is night blindness.