Insights into Your Cat's Eyesight

The next time you catch your cat staring at you with its big, luminous eyes, try this: Blink at kitty very slowly. There's a good chance your cat will blink right back.

Many feline fanciers suspect that cats communicate with their eyes. And animal shelter workers will swear that if you blink slowly at even a feral cat, the animal often calms down. Cats also use their eyes to intimidate prey and even each other, as a way of establishing dominance.

And for their size, this animal has a lot of eye to work with. If our eyes were as big as those of any cat, in terms of their largeness per head size, our eyes would be eight inches long, each. Even more, a cat's eyes also bulge slightly, giving them excellent peripheral vision.

You may have noticed that, while you stumble around in the dark looking for the light switch, your cat is calmly navigating its way around the furniture. You may have also noticed that sometimes in a dim room, your cat's eyes will glow eerily. As nocturnal predators, cats have developed excellent night vision. Cats have vertical irises, which can narrow to the tiniest sliver in bright light or open to cover 90 percent of their eye area, enabling the pupil to capture even the smallest amount of light. In addition, a cat has a shiny membrane in the back of the eyes called the "tapetum lucidum," which helps to reflect light back through the retina, enabling the animal to see better in low light situations. That said, there is a limit: cats still can't see in total darkness.

As anyone knows who has watched a bug try to get across the floor and not get pounced on by the cat, this animal is acutely attuned to movement. In our own eyes, rods react to intensities of light, while cones react to color. A cat's eyes have more rods and fewer cones than ours do. This means that while we have better color vision, a cat can detect motion better. But all that sensitivity to motion comes at a price: Cats don't actually see close objects very well. After all, what's the advantage of seeing the mouse once it's in your paws?

Cats also have a third eyelid to protect their eyes as they stalk prey through grass and underbrush. Called the "nictitating membrane," this eyelid rests at the inside corner of the eye. If a feline's eyes are inflamed or irritated, you may see this membrane start to protrude. If a cat is seriously ill or debilitated, the membrane will partially cover the eye (and that's a definite signal to take your pet to your veterinarian).

While it's not completely certain what colors your cat is able to see, there's no doubt that the color of a cat's eyes are simply beautiful -- copper, gold, green, orange, yellow, blue, and lavender. Many cat owners say they chose their cat because of its eye color. Given the power of the cat's eyes, perhaps they were happily mesmerized.