Why Do My Dog’s Eyes Roll Back When Sleeping?

Photo by Nathan Dumlao on Unsplash

A dog staring at you with white eyes  seems like horror movie stuff, but rolling their eyes back is a natural thing for many dogs, so if you happen to witness such an unusual sight there’s no reason for concern. 

Some breeds are more prone to this, but it can happen to any dog.

This is related to certain physical characteristics of their heads and eyes, as well as to their sleeping pattern, and we’ll examine all the reasons dogs roll their eyes back while sleeping.

Also, we’ll look into why dogs roll their eyes backwards while fully awake, and there are more reasons for concern when that happens.

Why does my dog roll his eyes back while sleeping?

To understand a dog’s eyes movement, we have to first look at their sleeping pattern, which is quite similar to that of humans. Dogs experience two types of sleep stages:

  • Rapid Eye Movement is the stage when the dog dreams. You can observe this movement whether the dog has the eyes fully closed or not.
  • Short Wave sleep or non-REM  stage is when the mental processes are quiet, but the body is not totally relaxed, so the dog can easily wake up at the slightest noise.

However, in many cases, when the owner worries about their dog rolling his eyes back in his sleep what they’re actually observing is the third eyelid, aka the  nictitating membrane, which is present in various animal species, like birds, reptiles, cats or dogs.

This translucent third eyelid, also referred to as the haw, is hidden under the lower eyelid and its main purpose is to offer extra protection to the eye, by removing dust and debris.

Birds and reptiles have a full membrane which they can control independently of the normal eyelids. Dogs only have a vestigial nictitating membrane, which they cannot control separately. It moves in sync with the normal eyelids, but while they’re sleeping it often happens that the third eyelid is exposed. It still does its fundamental job of protecting the eye, but it can also freak out a pet owner.

Why do dogs sleep with their eyes open?

Naturally, if the dog slept with the eyes closed you wouldn’t observe any disturbing white part, so why do they keep their eyes fully or partially open while they’re sleeping?

One theory is that sleeping with their eyes open is a defense mechanism, which can be traced back to the days when canines lived in the wild.

An approaching predator would be fooled into thinking the dog is, in fact, awake and alert, so they’d think twice before attacking. That was thousands of years ago, but your furry friend still has many of his natural instincts.

When the eye is covered by the third eyelid it can still receive some external stimuli and transmit them to the brain.

Even if the dog doesn’t have to worry about enemies, this characteristic is most useful allowing your pet to observe you’re quietly preparing to go out or breaking open a can of his favorite biscuits. Don’t be surprised if your dog wakes up and catches you in the act.

On the other hand, some breeds are more prone to this because of the shape of their heads and eyes.

Flat-faced dogs, like pugs or French bulldogs, which have big bulging eyes are more likely to keep their eyes partially open when they are asleep.

Some dogs can sleep with their eyes fully open and it’s most confusing for their owners.

You see the dog staring creepily at you, you talk to him, but there’s no response whatsoever. It’s only when you get near the dog that you hear a gentle snoring, indicating that the animal is in fact fast asleep.

Is my dog having seizures in his sleep?

When a pet owner sees his dog with the dog lying on the floor with the white of his eye showing, they often worry the dog might be having a seizure. Often associated with epilepsy, seizures can have many causes like:

  • Poisoning
  • Low or high blood sugar
  • Electrolyte imbalances
  • Anemia
  • Liver disease
  • Stroke
  • Tumors

Most often, dogs go through a seizure when they are awake or immediately after waking up. Yet, dogs can also have a seizure while sleeping, so it’s important to know how to tell one from a common thing like sleeping with the eyes open.

How to tell if the dog is having a seizure in his sleep?

When they’re dreaming, dogs often twitch and move their legs and this scares an owner even further. However, you should not confuse normal twitching with the convulsions caused by a seizure. When a dog is going through a seizure his legs become rigid and he experiences full body convulsions. That’s completely different from a dog randomly moving his legs while he dreams that he’s out chasing squirrels or fetching a stick.

Also, a dog having a seizure will often pee or defecate as he has no control over his body, which is not the case with a dog sleeping and dreaming.

As a rule, you shouldn’t wake up a dog when he’s dreaming, even if you might be concerned about their twitching and growling. It is possible that your dog is having a nightmare, but you should disturb him anyway. Actually, if you wake the dog in the middle of a nightmare he might be confused and act aggressively.

If you are very concerned your dog is having a seizure rather than dreaming, try talking to him gently. If he’s simply dreaming he will eventually wake up whereas a dog having a seizure will remain unresponsive.

If your doubts persist, you should see a vet to rule out a serious problem behind your dog’s unusual sleep behavior.

What causes my dog’s eyes to roll back while he’s not sleeping?

In most cases, it’s just one of the eyes that seems to be rolling back, but you might also notice unintentional weird movements in both eyes. This can be caused by old age, but it might also be a symptom of various conditions. Here are the most common causes.

Eye injury

When a dog moves just one of his eyes in a strange way, it probably has to do with the third eyelid. Since it serves to keep the eye clean, the inner eyelid might become damaged.

Also, the third eyelid might come up when the dog scratched his eye or has conjunctivitis. At the same time, the third eyelid might act up in response to some pain in the eye region. Such pain can be caused by an injury or infection.

If that is the case, you should see a vet and have some eye drops prescribed to treat the underlying cause.


Nystagmus is defined as a jerking movement of the eyes, which can be either an up and down movement, or a side to side movement. It is a serious reason for concern as nystagmus can be a symptom of a vestibular disease.

A vestibular disease affects a dog’s balance and it can appear suddenly. It may be caused by an infection to the inner or middle ear, hypothyroidism, a trauma or injury, a tumor or the ingestion of certain drugs that are toxic to the delicate balance mechanism in the inner ear.

Besides the irregular eye movement, other symptoms of vestibular disease include

  • Loss of balance
  • Head tilting
  • Falling (usually in the direction of the tilt)
  • Confusion
  • Inability to walk or stand

In most cases, rapid medical intervention will help the dog get back on his feet in a few days.

Tumors or cysts

Tumors that affect the neurological system can also cause irregular eye movement. They might even cause an abnormal growth of the third eyelid, triggering jerking movements of one or both eyes.

Cysts, on the other hand, are defined as lumps forming under the skin. If they’re in the eye region, they might cause weird eye movements. Cysts are usually benign, but as they cause great discomfort to the dog you should have your pet examined by a vet.


This is a condition in which the dog’s brain cannot control the eye muscles to work together. The result will be the eyes moving in different directions. This condition is often associated with old age, but it can also be triggered by vestibular disease or tumors.


Abnormal eye movement can be caused by a stroke, which is the result of a lack of adequate blood supply to the brain. A stroke can be caused by the obstruction of the rupture of a blood vessel and will often appear without any warning signs.

A stroke can easily be confused with a vestibular disease as they have many similar symptoms, including jerking eye movement, head tilting and loss of spatial awareness and balance. If you notice such worrying signs in your dog, don’t hesitate to see a vet.

Cherry eye

Cherry eye is an inflammation of the third eyelid gland and can cause irregular eye movements, besides the obvious discomfort. This problem is easy to spot as the haw becomes a swollen and bright red mass, hanging over the lower eyelid, close to the nose and muzzle. To prevent permanent damage to the third eyelid or the eye itself, cherry eye requires immediate medical treatment, which might involve surgery.

Closing thoughts

When your dog seems to roll his eyes back in his sleep, there’s no need to be alarmed. Probably, it’s just that the dog is dreaming, which also explains the twitches, so you don’t have to jump to the conclusion that the dog is having a seizure.

Many dogs sleep with the eyes at least partially open, which allows you to see the third eyelid, and this is perfectly normal.

However, jerking eye movements of the eyes, especially when the dog is awake, can be a symptom of various diseases. If you notice other worrying signs, it’s best to see the vet.