Guide to How a Cat's Eyes Work

Few things are as mesmerizing as looking into a cat's eyes; as anyone who has ever had the pleasure of a feline companion can attest to. Cat's speak volumes through their looks. And a cat's eyes glowing in the dark as they prowl and pounce is a very interesting sight. Have you ever though to wonder how a cat's eye works? Why do they glow in the dark? Why are their pupils slits? Read on for answers to these questions and more.

All cats pupils are elliptical. From domestic house cats to the big cats you see at the circus, like Tigers; they all have slits for pupils in brighter light. This protects their sensitive retinas in bright sunlight. The difference in pupil appearance from cats to humans is because humans have a circular shaped muscle that contracts the pupil and cats have two shutter like muscles that give the slit shape to the pupils.

The dark is where a cats eyes really shine, so to speak. Cats can see clearly with only one sixth of the illumination that humans need to see. Their pupils open so wide that they appear round when their is an absence of light. While a cat's nocturnal vision is far better than a humans, they cannot see in total darkness.

When you see a cats eyes glowing green in the darkness, you can attribute this to an eye feature that is present in some animals, but not in humans. The tapetum lucidum is a reflective layer behind the retina of a cats eye that reflects incoming light and bounces it back off the light sensor cells in the retina, like a mirror. This makes optimum use of the available light and makes it easier for cats to hunt at night.

Cats also have a third eyelid, called a nictating membrane that protects their eyes from dryness and damage. Cats are prone to the same type of eye problems that we are so you should take them to a vet at the first signs of problems. A partially closed nictating membrane can signal problems, as well as eye discharge, eye redness, film over the eyes, irritation, bulging eyes, or changes in appearance or difference in appearance between eyes.

Some interesting facts we learned during our research, were that cats are not colorblind, but they don't see colors as enhanced as we do. Most white, blue eyed cats are deaf. And the most fun thing we learned is that cats "kiss" with their eyes. So, the next time your cat stares intently into your eyes for a few moments then slowly blinks, consider yourself kissed!

Resources
About.com, What You Can Tell By Looking Into A Cats Eyes

About.com, Why Cats See Better At Night

Why Do Cats Eyes Glow In The Dark?

Cat Eye Problems - Signs To Be Aware Of