Cats’ eyes glow because of a structure called the tapetum lucidum (“bright tapestry”).
How It Works
Located behind the retina, this reflective layer acts like a mirror. Light that passes through the retina is bounced back, giving light-sensitive cells a second chance to absorb it. This amplifies available light and improves night vision.
Why Cats Need It
As crepuscular predators, cats hunt at dawn and dusk, so enhanced low-light vision is a major advantage.
Dogs, horses, cows, and some other animals also have a tapetum lucidum, though its structure varies by species.