Fish who live in ocean abyssal depths, such as the hatchetfish, have very large lenses to collect all available light. the flashlight fish produces its own illumination with the aid of a colony of bioluminescent bacteria. the loris, who lives in the east indies, also has the large light-collecting lens seen in nocturnal animals. the south american douroucouli is the only nocturnal primate, and its eyes are so sensitive to light that it can go blind with prolonged exposure to daylight.