Why Do Cats Have Slits in Their Eyes?

Why Do Cats Have Slits In Their Eyes?

If you’ve ever studied your cat’s eyes, you may notice that its pupils have a different shape than yours or even your dog’s eyes. There’s one striking characteristic: a cat’s eyes have slits in their pupils, resembling those of snakes and crocodiles.

According to the Association for the Advancement of Science (AAAS), there’s a link between an animal’s pupil shape and how it gets food in the wild, but why do cats have slits in their eyes?

Cats have slits in their eyes because of evolution, with studies from the AAAs finding that pupil shape defines an animal’s place in the food chain. Those with slits, or “vertically elongated pupils,” are nocturnal animals who eat by ambushing their prey, so the shape is crucial to survival.

The rest of this article will discuss the benefits of elongated pupils, provide warning signs that something may be wrong with your cat’s eyes, and finally, determine ways to keep the cat’s eyes healthy from the start.

Benefits of Slits in Cats’ Eyes

Domestic cats are typically small and seemingly easy prey for larger predators. Weighing between 8 and 14 lbs (3.63 to 6.35 kg), the average house cat is no match for most other animals.

In fact, even a large domestic cat breed, such as the Maine Coon, will only grow to about 16 in (40.64 cm) tall and may weigh up to 25 lbs (11.34 kg).

Though this cat’s size provides a regal appearance, it’s still too small to be an equal match for other animals without having a few bonus gifts from nature.

One of those gifts is the ability to sleep all day and play much of the night, but it is, at least in part, because of their size and innate instincts that cats are typically most active at night.

It is because of this nocturnal activity and the fact that cats are loners by nature that cats need these slits or elongated pupils to maintain their keen eyesight.

The benefits are amazing and evidence of how nature takes care of itself. Benefits of elongated pupils, or slits in a cat’s eyes, include:

Superior Night and Peripheral Vision

Cats do not detect color as efficiently as other animals and they are pretty near-sighted. Although they seem to pounce on unsuspecting prey out of nowhere, they actually need to be no more than 20 ft (6.10 m) from an object to see it clearly. Even with this nearsightedness, their night vision is impeccable.

Also, because of these elongated pupils, they have a broader peripheral vision than humans do, which is why they’re masters at catching bugs and birds that often see the cat only after the cat has pounced.

Nature’s gift to cats is most helpful because by having a broader range of sight peripherally, they can see predators more quickly and react to that threat. They can also see and pounce on prey more readily.

Protection From Bright Lights

Although cats seem mesmerized by bright lights, another benefit of having slits in their eyes is that this trait allows their eyes to dilate fully, allowing more light in so that the bright light doesn’t impact the cat’s ability to see.

This trait is essential for animals that must find their prey at night.

Better Judgment of Distances

Another benefit cats have due to their unique pupil shape is that they have a different depth of field so that they focus differently on their prey.

Studies at AAAS reveal that these slits in the cat’s eyes create a depth of field in which the cat has an advantage in ambushing its mark because it can focus on different points, and anything that isn’t being focused on will blur.

The object of focus will be crisp, making it easier for the cat to estimate distances.Why Do Cats Have Slits in Their Eyes?

Cat-owners can understand this focal point/blur combination by considering photography. The best pictures are often those that have a different depth of field set so that the focus is clear, but the rest of the image is blurry.

What is blurry does not matter, just as when the cat focuses on its prey. What is out of focus is only a distraction to the cat, so nature allows the cat the ability to ignore it using these elongated pupils as a photographer would adjust a depth of field setting.

Is There a Problem With My Cat’s Eyesight?

Although this elongated pupil looks different to us, the cat sees as perfectly as it was ever supposed to. Still, readers interested in their cats’ pupils may be sensing — or at least concerned — that there may be problems with their cat’s eyesight.

It’s surprisingly hard to tell if a cat has eyesight problems in the beginning stages of vision failure. This difficulty in detection is partly because the cat will quickly rectify behaviors we may look for, including bumping into furniture or hesitating to jump before we realize there’s a problem.

For example, you may not see that the cat has bumped into the couch five times because after being stopped by it multiple times, the cat now knows how many steps to stay away from that area.

The cat changes its behavior and avoids pain but has also erased your first indication that there’s a problem with its vision.

However, there are ways to know when the cat’s eyesight is a problem. For example, the cat may:

  • Show a reluctance to jump down but still climb normally
  • Walk in a crouched position
  • Have a change in eye appearance
  • Visible discharge
  • Constant blinking
  • Redness or Swelling
  • Display unusual-sized pupils

If the change is as apparent as visible discharge or redness and swelling, it could be that the cat has been unable to clean its eyes properly, and cleaning the eyes with a gentle wipe, like the Arava Pet Eye Wipes, may be all that’s needed.

In that instance, there’s an easy fix. However, any changes in cat behavior or eye appearance may indicate that a change in eyesight may have occurred, so seeking veterinary attention is advised.

Can I Promote Eye Health in My Cat?

The saying, “An ounce of prevention is worth a pound of cure,” certainly applies here. Although we seldom pay attention to our pet’s eyes unless they’re looking at us longingly as we have to drop them off at the kennel, there are ways to help cats maintain their incredible eyesight.

The writers at Animal Wellness Magazine expose that the key to maintaining a healthy vision is to support a robust immune system.

In the blog, Ingrid King explains that many eye problems come from the herpes virus, which most often appears in animals with low immune systems. Another simple fix is to eliminate stressors such as boredom and obesity.

Immune support begins with quality food and can be supplemented with various products on the market, such as powders (like Dr. Bill’s Feline Immune Support) and liquids (like MaryRuth’s Organic Elderberry Syrup Black Sambucus Liquid Drop).

Final Thoughts

Pets enrich our lives, and they invoke curiosity about things such as why their eyes are shaped differently from ours. While the reasons for these differences almost always return to survival, the answers are no less intriguing.

The responses to those questions lead us to more knowledge and better ways to care for our furry friends. Sometimes those answers even make us aware of the importance of some things we take for granted–like our cat’s eye health.

They may say that “curiosity killed the cat,” but in this case, the owner’s curiosity may save the cat’s eyesight.