Whether your cat’s eyes are green, hazel, amber or even blue, they’re probably the most beautiful pair of eyes in the world to you. But aside from their beauty, there’s so much more to a cat’s eye, especially compared to our own!
The Anatomy of a Cat’s Eye
Although a cat’s eye is very similar to a human eye, there are some differences when it comes to how and what we see compared to a cat.
Whereas our pupils are round and dead centre in our eyes, a cat has pupils that can change from round to a slit in, well, the blink of an eye! The size and shape of their pupils change dependant on the amount of light hitting them, the same as us, but the ability is much more marked in a cat meaning that their delicate inner eyes are much better protected from direct sunlight.
While we only have two eyelids, top and bottom, your cat has a third eyelid that comes from the corner of the eye as an added layer of protection. Your cat’s third eyelid is a good indicator of something being wrong, so if you notice that just one of them is visible there might be some damage to that eye, and if both are visible it could be a sign that he’s suffering from an illness.
As cats are naturally nocturnal predators, they have a reflective layer at the back of their eyes called the tapetum, which is why cats’ eyes glow in the dark. It also means that they have double the amount of light hitting their retinas, and gives them good night vision; all the better for spotting their prey in the darkness.
Fascinating Facts about Cats’ Eyes
- Cats can’t see perfectly in the dark, although they do have better night vision than us humans. When it’s pitch black outside and there’s no light at all to hit the tapetum, they have to rely on other things to guide them; sound, scent and their sensitive whiskers.
- Although it used to be thought that cats couldn’t see colours at all, more recent studies have shown that cats can indeed distinguish different colours, although the ability is much less than in humans.
- Cats don’t see in as much detail as humans do, and this is partly because they have a wider range of vision than us. While our visual field is 180 degrees, cats’ is 200 degrees, which means that the outer ranges of their vision have less clarity. Cats’ retinas also have less cones than human retinas, which gives them better night vision but less clarity in daylight.
- Cats’ eyes are an essential part of their communication with other cats, and you can use your own eyes to ‘speak’ to your cat, you just need to learn the language. The level of openness of a cat’s eyes signifies how alert he is, so you’ll often find your cat has wide open eyes around strangers; that’s because he doesn’t know whether he can trust them. Similarly, when you’re petting him, he probably has half-closed eyes, and that means he totally trusts you. Staring is seen as aggression in the cat world, so when a human stares directly into a cat’s eyes, the cat is going to be nervous. To show a cat you’re not a threat, try doing a ‘slow blink’ so he knows you’re friend, not foe. If he blinks back at you, you’ve successfully made a new feline friend.
Image: S.Carter via Flickr