Why do dogs’ eyes seem to glow in the dark?FamilyPet
Dogs’ eyes seem to glow in the dark because they possess a reflective layer, called a Tapetum Lucidum, which acts like a mirror, reflecting light. When light enters the eye, it is captured by photoreceptors that send information to the brain. In dogs, if light isn’t initially absorbed by a photoreceptor, it bounces off the Tapetum Lucidum and enters the eye again for another shot at being received.
Depending on the amount of pigment in the retina, different shades of glowing light will be seen when looking at a dog’s eyes at night. Some dogs have pigments that allow for the Tapetum Lucidum to appear turquoise or blue in the dark, while others’ will look yellow or red.
The presence of the Tapetum Lucidum allows dogs to see extremely well in dim light, because light has a better chance at entering the eye than without the reflective layer. Additional animals that possess the Tapetum Lucidum include horses, cattle, cats and deer.