Incoming light from a distant light source, such as a bioluminescent flash, is imaged efficiently by the mirror on the right onto a point on the retina, left (Image: Julian Partridge, University of Bristol) A spookfish. The red eyes are the spookfish’s tubular eyes, which point upwards. The black bumps on the side of its head are the diverticular eyes; these point downwards, so they do not reflect the flash-light (Image: Dr Tammy Frank, Habor Branch Oceanographic Institution)
THE deep sea is full of surprises, and the four-eyed spookfish is up there with the best of them. It is the…
