The Glow of Animal Eyes

Glowing eyes in the dark – creepy or cool? That might depend on the situation in which you encounter those eyes. It is safe to say glowing animal eyes definitely get your attention. But why do some animal eyes glow in the dark? This piece from NPR’s “All Things Considered,” explains that animals that are out and about at night have a reflective surface – called a tapetum lucidum – behind their retinas to help them see better in the dark. The article notes, “when light enters the eye, it’s supposed to hit a photoreceptor that transmits the information to the brain. But sometimes the light doesn’t hit the photoreceptor, so the tapetum lucidum acts as a mirror to bounce it back for a second chance.” So what animals have the most intriguing nighttime eyes? Owls would probably rank high on the list along with cats, dogs and some reptiles. Which animals have the most intriguing eyes?