Tapetum Lucidum

Some of you humans may not be aware that cats are nocturnal mammals, which means that we are most active at night and sleep most during the daytime. Since we are primarily hunting our dinners at night (although my hunting consists of going to my dinner bowl to see if I left a piece of kibble behind), our eyes have a special thing called tapetum lucidum.

Tapetum lucidum is Latin, but I don't speak Latin. All I know is that it means I have flashlight eyes so that I can see my dinner, and everything else in the dark. I sometimes forget that my humans don't have this nifty feature in their eyes, and so I forgive them when they trip over me in the dark. Boy it really makes me appreciate being a cat instead of a human. Who wants to be blind in the dark?

Anyway, scienceenotes.com has this to say about my great eyes and why they are the way they are.

"Cats' eyes shine in the dark due to the presence of a light-reflecting surface called the tapetum lucidum. The tapetum lucidum, located behind the retina, is composed of fifteen layers of special glittering cells of the substance guanine.

The tapetum lucidum reflects any light that is not absorbed as light passes through the retina of the eye. The reflection by the tapetum lucidum allows the retina to absorb extra light, which aids the cat's night vision. Another consequence of the tapetum lucidum is that it causes the cat's eyes to shine in dim light, when the light hits the eyes at certain angles.

A cat's shining eyes usually appear greenish or golden. The eyes of the Siamese cat reflect a luminous ruby red."

You'll notice it's midnight when I'm posting, because that is when I'm most awake. I chill out with my humans until they fall asleep, but then I rule the house. The night is mine!