Why do the eyes of some animals glow in the dark?

Some animals have a special, reflective surface right behind their retinas, called the tapetum lucidum, which helps animals see better in the dark. When light enters the eye, it hits a photoreceptor that transmits the information to the brain. But sometimes light doesn’t hit the photoreceptor, so the tapetum lucidum acts as a mirror to bounce it back for a second chance.