Why Do Cats’ Eyes Shine at Night?
A cat’s eyes shine at night because they reflect light. Cats’ eyes contain a special mirror-like lining. This reflecting lining, which is called the tapetum lucidum, gives cats the ability to see in dim light because it collects even the faintest rays of light.
Lying immediately behind the retina it reflects visible light back through the retina, increasing the light available to the photoreceptors, though blurring the initial image of the light on focus. The tapetum lucidum contributes to the superior night vision of cats too.
This shiny lining also reflects the light from a flashlight or the headlights of a car and causes the cat’s eyes to glow brightly. Cats are not the only animals with eyes that shine at night.
Deer, raccoons, bullfrogs, and most other animals that remain active at night have eyes which reflect light, also.