Have you ever looked at your cat and wondered how they see the world? Do they see things the way we do—the same colors and shapes? Do they experience color-blindness? Do they have night vision that enables them to see exceptionally well in the dark?
If you’ve ever wondered how a cat’s vision compares to human vision, you’re in the right place! Here you’ll find all the differences (and similarities) between the two and find out how your favorite feline’s vision stacks up compared to yours. Read on to find out more!
At a Glance
Overview of Cat Vision
While we can’t possibly know exactly what a cat sees, we can figure out how they see the world by looking at the structure of the eyeball and how it compares to a human’s vision.
Structure of the Cat Eye
A cat’s eye is actually quite similar to a human’s. Like us, they have the sclera (or white of the eye, which is the outer layer of the eye that is covered with conjunctiva (a membrane). Then there’s the clear dome on the front of the eye called the cornea, responsible for allowing light in. And like humans, cats have the iris, which is responsible for the color of their eyes and controlling how much light enters the eye. The cat eye contains a pupil, too, that changes size to let in more or less light.
How else is a cat’s eye similar to our own? A cat’s eye also contains a lens that is responsible for becoming thicker to allow more focus on objects that are closer. The lens is an area where a cat’s eye differs from a human’s, though, as the changes a cat’s lens goes through appear to be more limited than what a human’s lens can do.
Then there’s the retina, where perhaps the biggest differences lie. Retinas in both cats and people contain photoreceptors, with the main types being cones and rods. Cats have the same three color cones that humans do, but they are suspected only to be able to see colors in the way a colorblind person would. However, cats have many more rods than humans do, which gives them wider peripheral and night vision.
Finally, cats have what’s known as the tapetum, a reflective portion of the eye that can magnify the amount of light coming in—this also helps boost their night vision!
Visual field means the area a human or animal can see when they have their eyes focused on one point. So, peripheral vision essentially—what can be seen to the side, straight ahead, below, and above where one is looking. Cats have an advantage here because their visual field is 200-degrees, which is wider than a human’s.
Visual acuity is how clear (or unclear) one can see. You’re probably familiar with the phrase “20/20 vision”; well, a cat’s can be anywhere from 20/100 to 20/200. That means what a human can see from 100-200 feet away, a cat has to be 20 feet away to see clearly.
Why is a cat’s vision so much blurrier than our own? Likely because they don’t have the necessary muscles that will enable the shape of their eye lenses to change and thicken in order to focus more.
Some believe cats can’t see colors at all, but only in shades of gray. However, cats are actually what is known as a trichromat, which means they have three cones in their eyes that should enable them to see the colors green, blue, and red. You’d think that would mean they’d see colors just as a human does. Instead, cats are thought to see similarly to a human with color-blindness. So, though they don’t have trouble seeing blues and greens, colors on the red scale can appear as colors closer to green or blue rather than shades of red.
As for the number of rods cats have in their retina, they have many more than humans. These rods are what allow them to have the broad visual field they have, as well as improve their ability to see in low light and dark. Because they have so many rods, it’s estimated that cats can see in approximately 1/6 the amount of light a person needs to see clearly.
A cat’s eye also has something called a tapetum that is behind the retina—this is thought to boost their ability to see at night. Why is that? Because the cells in the tapetum reflect light going between the cones and the rods back to photoreceptors in the eye. This reflection enables kitty to pick up on any tiny bit of light that may be around (and it’s why their eyes seem to glow when it’s dark!).
Overview of Human Vision:
Human vision differs from a cat’s mostly in the way we see a more comprehensive range of colors more vibrantly, can see and track objects that move slowly, and are better able to see objects from further away.
Structure of a Human Eye
As we said when we covered the structure of a cat’s eye, the human and cat eye are quite similar. For the most part, our eyes contain the same elements as a cat, such as a lens, retina, pupil, cornea, iris, and more—and these components function in the same way as well. The most significant difference between the structure of a human and cat eye is that a human eye contains more cones and fewer rods. This affects how wide our peripheral vision is and how well we can see in low light or darkness.
When it comes to a human’s peripheral vision, we have a bit of a narrower visual field than cats do. Where they can see 200-degrees in their visual field, we can only see 180-degrees. It makes sense, though, since cats can use their wider visual field to aid in hunting!
You may not have 20/20 vision as a human, but you’ll still likely see better than your kitty does. Humans can see with more clarity both items that are far away and those that are close because of the structure of our eye’s lens. Plus, things we see that move slowly would most likely look as if they are standing still to your cat!
Humans are trichromats as well, so we also have the three cones in our eyes that allow us to see red, green, and blue. This allows us to see a broad range of colors (unless you are color blind). The biggest difference between a human being trichromat and a cat being the same is we see a larger range of colors, plus we are able to see things more vibrantly. Simply put, our world is a little brighter!
Let’s face it; a human’s night vision is pretty lousy. While we get to see the world in vibrant multi-color due to the number of cones we have in the eye, we lose out on seeing in the dark because the human eye has fewer rods in the retina than a cat does. Still, it seems like a pretty fair trade-off!
As you can see, the way cats and humans view the world is more similar than one would think. This is because the structures of our eyes are nearly the same, with the main difference being in how many cones and rods we each have.
However, this near-identical eye structure doesn’t mean we see precisely the same. Even though cats are trichromats like we are, they are still suspected of having less ability to see the same number of colors as humans do (and likely see colors in duller shades than us). Cats win out when it comes to the range of their peripheral vision, though (all the better with which to hunt!). They also win for night vision, as they can see much better in the dark!
Featured Image Credit: Pixabay