Q&A: Do Dogs Sleep With Their Eyes Open?
No. In those instances where you swear that your dog is sleeping with his eyes open, it turns out you are actually seeing his third eyelid.
Keep reading for a more complete “do dogs sleep with their eyes open?” answer, including why dogs have a third eyelid and if your dog’s open-eye sleeping is actually a health problem…
CC Image “Baxter Sleeps With One Eye Open” courtesy of Austin Kirk/Flickr – Thx Baxter (& Austin)!
I mean, it’s an honest idea, right?
They’re lying there, perfectly still, maybe even drooling a little, and completely oblivious to anything going on around them.
Surely, they must be asleep?
We’ve had so many people ask:
“Do dogs sleep with their eyes open?”
…and even wondered a time or two for myself, that I decided to delve deeper into the topic to try to find some answers.
And here’s what I came up with.
It Isn’t Always What It Seems
Dog’s sleeping with their eyes open isn’t something that happens on a regular basis.
At least, not the way we might think it is.
It may seem like it at times, but they really aren’t actually sleeping with their eyes open.
To start with, if they did this on a regular basis, their eyes would become far too dry and they would experience a lot of eye health problems. It simply isn’t feasible for any living creature to sleep with their eyes open.
It’s just not healthy.
In fact, the only time this really happens is if the dog is under anesthesia.
They can’t blink at this time either, so when a dog is “sleeping” with his eyes open during surgery, the vet will put a few drops of ointment into their eyes to prevent dryness that can lead to other problems.
Trivia Time: Dogs Have A Third Eyelid!
In those instances where you might just swear that your dog is sleeping with his eyes open, it turns out you are actually seeing his third eyelid!
Did you even know they had a third eyelid?
I sure didn’t. But they do.
In fact, if you take a closer look, you’ll notice that you don’t actually see the dog’s eye color during this “sleeping with his eyes open” experience:
What you actually see is a light red or pinkish tissue that covers the eyeball. Scientifically, it’s called the haw, or the nictitating membrane.
It is responsible for keeping the dog’s eyeball moist while he’s sleeping.
That third membrane, or eyelid, is also good for keeping any loose debris or particles from attaching to his eyes.
It works sort of like a windshield wiper and keeps those particles swept off the eye.
(Which is great for an animal that can’t rub his eyes like we can.)
It can also function the same way a lymph node does, to help fight against infection, and it helps protect the cornea from injury.
The third eyelid also produces about fifty percent of the tears in dogs.
What’s interesting about this particular eyelid is that there are no muscles attached to it.
So how does it work?
It is completely passive and only gets initiated when the eyes roll back or around.
Why Does It Appear that Dogs Are Sleeping with Their Eyes Open?
While not every dog can appear to sleep with their eyes wide open, it’s a habit that is actually tracked back through the dog’s heritage.
The third eyelid is actually a defense mechanism!
The ability to appear as though he’s sleeping gives the dog the ability to rest but still appear attentive.
The overall goal was that animals larger than them wouldn’t hunt them.
It’s a natural, built-in instinct that just doesn’t seem to be leaving, even though there’s no longer a chance of them being eaten while they sleep.
Certain breeds are more prone to third eyelid activity than others are.
For instance, the Borzoi and the Greyhound both have third eyelid that will be easier to see than others, because their heads are longer. These are the dog breeds more likely to “sleep with their eyes open”.
Dogs that have shorter heads, such as the Pug and the Bulldog, usually won’t look like they’re sleeping with their eyes open.
However, (as we all know) anything can happen in the dog world…so we won’t chisel that last statement in stone!
When Does a Dog Sleeping With Its Eyes Open Signal A Problem?
There are lots of times you’re likely to see your dog sleeping with his eyes open.
And most of the time, there’s absolutely no cause to be worried.
However, as it goes with any pet, there are exceptions.
Sometimes a dog that sleeps with its eyes open could be having a seizure.
There’s a difference, however, between seizures and twitching:
- Seizures are caused by illness, factors relating to heredity or even the environment, and they are neurological in nature.
- Twitching is neurological as well, but it’s related more to the fact that your dog is probably dreaming.
If you’re concerned that your dog may be having a seizure, make sure to pay close attention to his eyes.
If he’s actually twitching, he will look peaceful and relaxed and you can chalk it up to a nice action-packed dream.
In the case of a seizure, your dog’s eyes will be wide open, but it will be a blank stare.
Also during a seizure, a dog can often have involuntary vocalizations, and involuntary movements such as thrashing, shaking or violent muscle twitches. They last longer than normal twitching, as well.
Another way to know for sure that your dog isn’t simply twitching, but instead, having a possible seizure, is the fact that a seizure can’t be stopped.
It has to run the course, whatever that may be for your dog, and the only thing you can really do is make sure he’s safe until it’s over.
A Dog’s Eyes Are The Windows To His Soul
We’ve all heard it said that they eyes truly are the windows of your soul.
And it’s true, to a certain extent.
For our dogs though, we might think they are sleeping with their eyes open, but they’re actually utilizing a third eyelid.
That leftover bit of heritage from their primal ancestors might not serve the same purpose, but it’s certainly a good topic of conversation. However, if you’re ever in doubt as to whether your dog is simply dreaming or if he’s having a seizure, make sure to see your vet as soon as possible.
How about you?
Do you have any great tidbits or information about your dog sleeping with his eyes open? If so, we’d love to hear about it, and we’re sure our readers will as well.