It’s a pretty strange sight—your dog is peacefully sleeping on the bed, but their eyes are partly open, unfocused, and looking out into space. As creepy as this may seem, it is common and usually normal.
Why Do Dogs Sleep With Their Eyes Open?
We really don’t know why dogs sleep with their eyes partially open, but there are quite a few theories.
Your dog is not fully asleep.
The most likely scenario is that your dog may only be partly asleep. In the early stages of sleep, dogs relax deeply but doze lightly. In this state, they may be relaxed enough to appear asleep but have not yet fully lost consciousness, so their eyes haven’t fully closed.
These dogs usually return to full awareness very quickly if stimulated. Often, just quietly saying their name is enough to return them to wide-eyed consciousness.
It’s instinctual for dogs to stay alert while sleeping.
Another theory about why dogs will do this is related to evolution. Animals in the wild need to maintain some degree of situational awareness. In fact, birds can put half of their brain to sleep, leaving the other half active. They can even fly while asleep!
Animals that are able to “keep an eye out” on their surroundings may have a definite advantage. It is possible that our pampered house pets have retained some of this protective instinct. They may be much more deeply asleep, but still have some part of their brain alert and functioning.
Some may also show a “raised third eyelid” (also known as a nictitating membrane) while they are asleep. This membrane is a partly clear, protective layer that covers the eye. It usually comes up from the corner of the eye nearest the nose, and often has a pinkish or yellowish hue.
Your dog may be in REM sleep.
Many dogs sleep with their eyes partly open during REM sleep, or the stage of sleep in which dreams occur. In this stage, you may see twitching, barking, and even eye movements.
Many people confuse this stage of sleep with a seizure, because the dog is unconscious but still showing movement, and sometimes vocalization. However, dogs that are experiencing a seizure often have much more violent movements, are impossible to arouse, and will often have eyes fully open and “staring into space” as opposed to the half-open, relaxed look of dogs that are sleeping.
Your dog may have an eye condition.
There may also be a medical reason behind why your dog seems to be sleeping with their eyes open. Some dogs develop conditions of the eyes or eyelids that make it difficult or impossible to close their eyes normally. These dogs will always sleep with their eyes open, not just sometimes.
These types of disorders are most common in dogs with short, smushed-in faces and big eyes, like Pugs or Boston Terriers. In breeds with huge, bulging eyes, their lids may be so small that they can’t normally close their eyes.
Dogs with narcolepsy may also sleep with their eyes open. If your dog falls asleep at inappropriate times, such as while eating, playing, or even going to the bathroom, they may have narcolepsy. In most cases, this condition isn’t subtle and will prompt a speedy visit to your veterinarian.
If you think your dog has a medical condition that makes it impossible to sleep with their eyes closed, or if you think your dog may be having seizures, schedule a checkup with your veterinarian. It can also be helpful to get a video of what your dog is actually doing at home to take with you to your appointment. A picture or video is often worth a thousand words in these situations!
When to Be Worried About Dogs That Sleep With Their Eyes Open
In most cases, it’s completely normal for dogs to sleep with their eyes open or partly open, or even do some twitching and “running” in their sleep.
If your dog awakens easily, or seems to be acting normal when they do wake up, it is probably nothing to worry about. In these cases, you can just let your dog sleep if you see them sleeping with their eyes open. After all, no one likes to be disturbed during a nice, restful nap, right?
If you see any of the following, take your dog to the vet:
Your dog doesn’t seem normal when they do get up—they have trouble walking, fall over, or seem disoriented (it’s possible they were having a seizure)
Your dog is falling asleep in strange places and at odd times—like while playing outside
Featured image: iStock.com/JaneFaizullin