Why Does My Cat Sleep With His Eyes Open?

Cats have plenty of quirky sleeping habits, from curling into impossibly small positions to suddenly taking over the warmest spot in the house. One habit that can look especially strange, though, is seeing your cat asleep with his eyes partly or even completely open. It can be a little unsettling, especially when he appears to be staring into space while clearly snoozing.

In most cases, a cat sleeping with his eyes open is completely normal. Cats have several features that protect their eyes while they sleep, and their light sleep patterns can make it look like they are awake when they are actually resting. However, there are situations where sleeping with the eyes open can point to an eye problem or another health issue.

Why Do Cats Sleep With Their Eyes Open?

Cats sometimes sleep with their eyes partially open because they don't always enter a deep sleep immediately. During lighter stages of sleep, your cat may relax without completely closing his eyelids. You might see just a small portion of his eye, or his eyes may appear slightly open while he remains completely still.

Cats also spend a significant a lot of their sleeping time in the lighter stages of sleep. Their ancestors needed to remain alert to potential predators and other dangers, so cats developed sleep patterns that allow them to rest while remaining relatively responsive to their surroundings.

That doesn't mean your indoor cat is expecting a predator to walk through the door. It simply means that his natural sleeping behavior still reflects the instincts that helped cats survive in the wild.

Cats Have a Third Eyelid

Another reason your cat may appear to sleep with his eyes open involves something called the third eyelid, or nictitating membrane. Cats have this thin, translucent membrane in the inner corner of each eye.

The third eyelid can move across the eye and provide protection and moisture while your cat sleeps. When your cat's regular eyelids aren't completely closed, you may sometimes see this pale membrane covering part of his eye.

Seeing the third eyelid while your cat is sleeping isn't necessarily a cause for concern. It can simply be part of normal sleep. However, a third eyelid that remains visible when your cat is awake can be a sign that something isn't right and deserves veterinary attention.

Is Your Cat Actually Sleeping?

Sometimes it’s hard to tell whether a cat with his eyes open is asleep. Cats can rest extremely quietly, and they may look almost completely awake during lighter sleep.

Watch your cat's body language. If his body is relaxed, his breathing is slow and steady, his ears aren't actively responding to sounds, and he doesn't react much when you move around the room, he is probably asleep or deeply relaxed.

You may also notice small movements, such as twitching whiskers, paws, ears, or the tip of his tail. These movements can happen during REM sleep, the stage associated with dreaming. Your cat may be having his own little feline adventure while looking as though he's simply staring at the wall.

Cats May Sleep With Their Eyes Open During REM Sleep

REM sleep is one of the deeper stages of sleep, and cats might display some unusual behaviors during it. Their eyes may move beneath their eyelids, and occasionally their eyelids may remain slightly open.

You might notice your cat's eyes moving, his paws twitching, or his whiskers moving while he sleeps. Some cats even make tiny noises during dreams.

Seeing a cat sleeping with his eyes partially open during this stage can look strange, but it doesn't necessarily mean that he is uncomfortable or awake.

Why Does Your Cat Sleep With One Eye Open?

You may occasionally notice your cat sleeping with one eye partially open while the other eye stays closed. This can also happen during lighter sleep and doesn't automatically indicate a problem.

Cats can remain partially alert while resting and keeping one eye slightly open allows them to monitor their surroundings. In a comfortable home, this behavior usually doesn't mean your cat feels unsafe. It can simply be another example of the way cats naturally balance rest with awareness.

If the eye remains open frequently while your cat is awake or you notice redness, discharge, squinting, swelling, cloudiness, or other changes, it's worth having your veterinarian examine him.

Can Cats Sleep With Their Eyes Completely Open?

Yes, some cats can sleep with their eyes completely open or almost completely open. While this can look unusual, it can happen naturally, particularly during certain stages of sleep.

Some cats simply have more noticeable sleeping habits than others. You may even see your cat looking directly at you while you're convinced he's awake, only to discover that he doesn't respond because he's actually fast asleep.

A cat's eyes being open during sleep isn't automatically a sign that something is wrong. The important thing is whether his eyes look healthy and whether he acts normally when he's awake.

When Sleeping With Eyes Open Could Be a Problem

Although sleeping with the eyes open can be normal, there are times when an eye that doesn't close properly can indicate a medical issue. Cats need to blink and close their eyelids to protect the surface of their eyes, so an inability to completely close one or both eyes can allow the eye to become irritated or dry.

Conditions affecting the eyelids, facial nerves, or muscles around the eye can sometimes interfere with normal blinking. Eye injuries, inflammation, infections, and certain neurological problems can also affect how well a cat closes his eyes.

Pay particular attention if your cat is squinting, excessive tearing, eye discharge, redness, swelling, cloudiness, rubbing at his or her eye, or sensitivity to light. A change that appears suddenly is especially important to have checked by a veterinarian.

When Should You Take Your Cat to the Vet?

A cat sleeping with his eyes open usually isn't an emergency by itself. However, a veterinary examination makes sense when the behavior is new, happens consistently, or occurs alongside other changes.

Contact your veterinarian if you notice:

Your cat cannot completely close one or both eyes while awake

Redness, swelling, cloudiness, or a change in the appearance of the eye

Excessive tearing or eye discharge

Frequent squinting or blinking

Your cat repeatedly rubs or paws at his eye

The third eyelid remains visible while your cat is awake

Your cat seems painful, unusually tired, or behaves differently

Eye problems can worsen quickly, so it's better to be on the safe side and have your cat’s eyes examined by your vet in case it’s an eye infection or something else.

The Bottom Line on Cats Sleeping With Their Eyes Open

So, why does your cat sleep with his eyes open? In many cases, it's simply because cats have unique sleep patterns and may keep their eyes partially open during lighter sleep or certain stages of dreaming. Their third eyelid also helps protect and moisturize the eye while they rest.

If your cat looks comfortable and his eyes appear healthy when he's awake, there's usually no reason to worry. But if sleeping with his eyes open comes with redness, discharge, squinting, cloudiness, pain, or an inability to close his eyes normally, your veterinarian should take a closer look.

As strange as it may look, your cat staring at you with his eyes half-open may simply be his version of taking a perfectly good nap while watching you at the same time!