Why Cats’ Eyes Glow in the Dark
For a long time, the life of cats has been shrouded in mystery, myth, and superstition. People were frightened by how noiselessly these predators moved, by their secrecy, and their shrewd gaze. But most of all, they were afraid of the ability of cat eyes to glow in the dark with a mysterious light.
For a long time, the phenomenon of glowing eyes in cats remained unexplained, which is why people associated them with magic. However, after scientists examined the structure of the cat’s eye, this phenomenon was explained. 5-Minute Crafts would like to tell you why a cat’s eyes glow in the dark and sometimes look so frightening.
Why cats’ eyes glow in the dark
Cat eyes are a lot like human eyes. Their pupils are also capable of narrowing and dilating depending on how strong the light around them is. Just like in humans, a cat’s eye is able to perceive light reflected from objects and redirect it through the cornea, pupil, and iris to the lens, which is responsible for focusing the image. A cat’s eye also has a retina, which sends information about the image to the brain.
However, unlike humans, cats also have an extra layer tapetum lucidum in their eyes. This part is capable of reflecting light, returning it to the retina, and thereby causing the eyes to glow.
With the help of the tapetum lucidum, cats are able to catch the slightest rays of light and see in the dark. And in order to make the tapetum lucidum work as efficiently as possible, the cat’s pupils open so wide they are almost the size of the entire eye.
Domestic cats inherited this anatomical feature from their ancestors, who often hunted at dusk and dawn.
Why cats’ eyes glow so brightly even in dim light
As we have already figured out, cat eyes begin to glow at the moment when light is reflected from a layer called the tapetum lucidum. The strength of the glow depends on the properties of this additional membrane. The tapetum lucidum can amplify the light falling onto it by about 50 times. This is why cat eyes can look creepy in the dark.
Why the color of the glow can differ in different cats — like their eyes can glow yellow, green, or red.
The color of the glow of a cat’s eyes depends on the cat’s breed and the chemical composition of the tapetum lucidum membrane. Also, the age of the pet, the color of its fur, and the natural color of the eyes can affect the shade.
Can cats see in total darkness?
Street lights and even the moon can provide a cat with sufficient light for its night vision. However, cats can’t see in total darkness. To navigate in the dark, cats and their wild relatives use other senses (like their whiskers).
What other animals have eyes that can glow in the dark?
Different animals’ eyes have different colors when they are glowing. The pupils of some creatures can glow red, yellow, green, orange, or white — it all depends on the structure of the eye.
At night, you can see the glowing eyes of alligators, bears, deer, raccoons, chinchillas, possums, foxes, owls, rats, skunks, ferrets, camels, lemurs, kangaroos, and big cats (like tigers and panthers).
The eyes of domestic animals like rabbits, dogs, horses, pigs, goats, and cows can glow in the dark too.