Why Do Cats’ Eyes Glow?

Cats’ eyes might almost seem magical, but we promise, it’s all science. Let’s answer the question: why do cat eyes glow in the dark?

If you ever find yourself staggering to the kitchen in the middle of the night, half-asleep, in search of water, and you see a pair of glowing eyes staring at you — don’t panic. It’s more likely to be your cat than a monster,  keeping an eye on you in the darkness and wondering whether you’ll be giving them a surprise feed.

At slightly scary moments like this, you might wonder to yourself — why do cats’ eyes glow in the dark? How does it benefit them? Do other animals have eyes that also glow in the dark?

People have wondered about cats’ glowing eyes for years. In fact, the Ancient Egyptians believed that cats captured the glow of the setting sun in their eyes, a gift that kept them safe ‘til morning. The reality isn’t half as exciting or romantic. The real reason cats’ eyes glow in the dark is due to the structure of their eyes. Let’s take a look at the science behind cats’ eyes, why they glow and what other animals share this trait:

While you’re here, check out how cats communicate with their eyes

A (Very Brief) Science Lesson

One thing we have in common with cats is that we both have retinas — a layer of tissue at the back of our eyes near the optic nerve, made up of light-sensitive cells. These cells turn the light we see into electrical signals. Once converted, these signals are sent to the brain, which works out what we’re seeing. This happens instantaneously, quicker than an eye blink. 

Where we differ is that cats are, by nature, nocturnal creatures. They have evolved to hunt and be more active during night-time hours. During the day, cats lie around peacefully, snoozing and gathering their energy so that at night, they can get their exercise in — while keeping you awake!

Because cats are most active at night, when there is less natural light, their eyes have evolved into seeing better in the dark. This is why they have another layer of tissue we lack — something called the tapetum lucidum.

What is Tapetum Lucidum?

Tapetum Lucidum is Latin for “bright tapestry”. It is a thin layer of tissue lying just behind the retina. The tapetum is a retroreflector, meaning it can reflect visible light back through the retina. It’s usually present in nocturnal animals, especially carnivores and deep-sea creatures, although similar adaptations occur in some spiders.

Related: Check out these care tips for indoor cats to keep them mentally and physically stimulated

How Do Cats’ Eyes Reflect Light?

The tapetum is a layer of reflective cells behind a cat’s eye — light bounces off this layer, directing it back towards the eyes’ light-sensitive cells. This gives light a second chance of being detected, which improves the odds of a cat seeing something in the darkness.

However, not all the light is picked up a second time around. Some light simply passes back through the retina and travels out through the front of the eye. This creates the appearance of a glow, which is usually green, yellow or blue.

Why Do Cats’ Eyes Glow in the Dark?

So now we’ve got the mini biology lesson out of the way, let’s look at the “why?”  What’s the evolutionary purpose of glowing eyes? 

According to the American Veterinarian, the tapetum allows cats to detect both changes of light and motion — helping them to become more skilled at hunting, prowling and pouncing in the night-time hours.

Do Other Animals Have Eyes That Glow in the Dark?

When you think of glowing eyes, cat eyes are probably the first to spring to mind. But other animals also possess this striking feature, including some fish, sheep, horses, deer and ferrets.

So next time you see a pair of glowing eyes staring at you in the middle of the night, don’t worry. It’s simply the ambient light reflecting in your furry friend’s eyes. Although if you don’t have a cat, you might want to run.

Are you looking for quality cat furniture? Why not sign up to our newsletter to receive announcements of new products and special offers?

Our Core Values

Why Catipilla? Every product and idea we have is built around these core values.

Cat health and well-being.
Cats deserve the best. They deserve to be active, to be entertained, to stretch, to climb and rest. To play out all of their natural instincts where they feel safest – at home. Our range has been designed to cater for these instincts and provide the most enjoyment possible.

High-quality, space-saving additions to your home.
Every unit we design is built to last. We want you to have the confidence that our products will stand the test of time. We also want to ensure that cats feel secure on our units and have the freedom to roam wherever they please.

Sustainable products that last a lifetime.
All of our Catipilla products are made from 85% recycled material and we actively work to reduce our energy footprint by sourcing materials close to home.

Paws For Thought

Our blog is packed full of interesting tidbits and tips on caring for your cat. Whether you’re wondering how to keep your cat stimulated inside or want to learn more about their unique traits, our blog has a wide range of relevant topics to choose from. Click on an article below to get started.

why do cats sleep so much
Why Do Cats Sleep So Much?
 All of you want to watch them play, but they’re on their tenth nap of the day.  You might wonder —  why do cats sleep so much? Our cats might…
Why Do Cats Like Boxes?
Let’s get into the “if I fits, I sits” mentality — why do cats like boxes? And what’s behind this strange, adorable cat behaviour? If there’s one thing cats and…
Protect Furniture From Cats
How to Protect Furniture from Cats
We love our cats. We just don’t always love the effect they have on our sofas. To preserve our sanity (and our money), let’s discuss how to protect furniture from…

Find Us On Instagram

Menu