RPE65 and night blindness: Patients harboring the c.1430A>G (p.D477G) RPE65 mutation report symptoms of impaired night vision in the 4th or 5th decade but, in some, the onset of nyctalopia has been as early as the 2nd decade, while others have no subjective complaints of difficulties with vision in low light even in the 6th decade, which is indicative of some degree of incomplete penetrance (Figure 1).