Petsfanatics Forums - Cat Eyesight - How Your Cat Sees The World

Cats, like all other species, have adapted physically (and mentally) to a certain specialty. Understanding what this specialty is, and how it affects something as basic as cat eyesight, is fundamental to helping us understand our cats better.

Basically, Pussy Wuggums Is A Killer
As you probably already know, your cat is a predator. Being a predator is your cat's specialty. Even if that fuzzy lump of fur has spent its entire life eating cat food out of a bowl, its basic nature - and its specialized cat eyesight - is that of a dedicated and efficient hunter.

Like most hunters, a cat's eyes are on the front of its head, instead of at the sides. The eyes being located on the front has many advantages for a predator, including superior depth perception compared to eyes that are located on the sides of the head.

Superior depth perception, of course, is helpful if you're trying to figure out how far you have to pounce if you're going to land on your prey while hunting, and also comes in handy for tearing around the house and being able to gauge how far of a leap it is from the couch to the table!

If I Can't Run That Far, Who Needs To See It?
It might depend on your definition, but cat eyesight is probably somewhat nearsighted. In this case "nearsighted" means that cats can't see all that well too far out of their running range. This makes sense since a cat is a predator, and it's main objective is to catch its prey. If they can't run far enough to be able to catch it, nature has decided that it's really not that important for them to be able to see it clearly. Cat eyesight is also excellent for detecting motion, but not as good for seeing detail. By the way, your special cat may not be a long distance runner, but it can sprint at approximately 30 miles per hour!

Nighttime Vision
Remember, your cat is a predator. It's also a predator that likes to do much of its hunting at night, so its special cat eyesight has adapted to have exceptional abilities to help it see well in poor lighting. How well? It's estimated that a cat can see six times better in low light than a human. That brings us to the two things that allow for this special ability, the cat's pupils and its tapetum.

The Pupils
The one thing everyone seems to notice about a cat's eyes are the pupils. A human pupil is always round, but a cat's pupil can be either round (when it's dilated) or it can shrink in from the sides in stages until it is elliptical. When elliptical, a cat's eyes look like a slit, stretching from top to bottom. This special adaptation allows a cat to squint its eyelids, covering only part of the pupil but not all of it, thus giving it at least some manual control over the amount of light let in. If the pupil was simply reduced to a small circle, closing the eyelids would cover the pupil all together.

When opening (or dilating), a cat's pupils can dilate much faster than yours or mine. They can also dilate three times larger than yours or mine can. This lets in a lot of light, and is one of the reasons cats have their famous ability so see well in low light. They don't see well in total darkness, which is a popular myth, but it is true that their eyes' ability to dilate to such a large degree is part of the reason they have an exceptional ability to see in poorly lit conditions.

The Tapetum
Another reasons cats see so well in poor lighting is that they have a special membrane at the back of their eyes. This membrane is called a tapetum, and it acts a little bit like a mirror for light. After light passes into a cat's eyes, it hits the tapetum and is reflected back through the receptors again. This is an effective way of making double duty use out of any available light.

Have you ever noticed that when its dark, and a beam of light strikes your cat in the eyes, they seem to glow? That's the tapetum at work, reflecting the light back through the eyeball.

The Nictitating What?
Did you know your cat has an inner eyelid? It's called the nictitating membrane, or third eyelid. It helps to protect the cat's eyes. If your cat isn't feeling well this membrane will sometimes be partially visible, coming from the inner corner of the eye (or eyes). This may be a signal for veterinary attention.

On A Related Note...About Blinking
People who study cat behavior report that the way a cat blinks its eyes can be a strong form of communication. A relaxed, gentle, blink can communicate reassurance, and a slightly longer, slower blink is a way of communicating love. These communicative blinks not only work from cat to cat, but from cat to human (you knew your cat was trying to tell you something) and from human to cat (give it a try!).

On the flip side, a continuous stare will have the exact opposite effect on your cat. A prolonged stare feels threatening to your cat, and this may explain one of a cat's most curious behaviors. Often, when a cat enters a room with several people in it the cat will approach the person in the group who likes cats the least. This may be because the people who like cats will show interest in it by looking at it for prolonged amounts of time. Unintentionally, they may be making the cat feel as though it's being stared at, and making the cat feel uncomfortable. In this situation the cat will often approach someone in the room who is not a cat lover, because that's a person who is not staring at them.

Just For Fun
- You've probably noticed this, but cat eyesight is very poor for seeing anything directly under their chins or noses. If you put a treat right under their nose they can smell it. but can't see it. They'll have to look around a little first and usually pull their heads back a bit or step backwards before they see the goodie.
- Cats are not color blind. Cat eyesight doesn't see colors as well as humans do, but researchers feel confident that they can see some colors, at least to certain degrees.
- If a cat is white, and has a blue eye, it will most likely be deaf in the ear on the same side as the blue eye. If both eyes are blue, it is likely to be deaf in both ears.
- In relation to their body size, cats have the largest eyes of any mammal.
- Most cats do not have eyelashes.