Quick Answer: Dogs can sleep with their eyes partially open, which is why some owners notice their dog sleeping with eyes open during rest. This can happen because of normal sleep stages, relaxed eye muscles, or certain medical conditions. In most cases, it’s harmless—but sometimes it can signal eye or nerve problems that need veterinary care.
Seeing your dog sleep with its eyes open can be unsettling. You may wonder whether they’re really asleep, if something is wrong with their eyes, or if you should wake them up.
If your dog shows other unusual behaviors during rest, you may also find our guide on how many hours dogs sleep per day helpful.
The reassuring news is that this behavior is usually normal. Dogs have a third eyelid that helps protect and moisten the eyes even when the outer lids don’t fully close. However, in some situations, open-eyed sleeping can point to an underlying health issue.
In this guide, you’ll learn why dogs sleep with their eyes open, how to tell what’s normal from what’s not, and when it’s time to contact your veterinarian.
Is It Normal for Dogs to Sleep with Their Eyes Open?
Yes, in most cases it's completely normal. Dogs don't sleep exactly like humans do, and their sleep patterns explain a lot about this behavior.
Here's the thing: dogs have a third eyelid called the nictitating membrane. This thin, whitish layer sits in the inner corner of their eye and slides across to protect and moisten the eyeball. When your dog sleeps with eyes partially open, this membrane usually covers and protects the exposed portion.
So even though it looks like your dog is staring into space while unconscious, their eyes are actually getting some protection.
Why This Happens During Normal Sleep
Dogs cycle through sleep stages just like we do. During lighter sleep phases, their eyelids may not close completely. This isn't a problem—it's just how their bodies work.
You'll also notice this more in some dogs than others. Dogs who feel very safe and relaxed in their environment tend to sleep more deeply, which can actually result in more visible eye opening during certain sleep phases.
The REM Phase: When Things Get Really Interesting
Here's where it gets fun to watch (and sometimes a little alarming if you don't know what's happening).
Dogs experience REM sleep just like humans. During this phase, their brains are highly active—they're likely dreaming. And their bodies respond in ways that can look pretty dramatic.
During REM sleep, you might see your dog:
- Moving their paws like they're running
- Twitching their face, ears, or tail
- Whimpering, barking, growling, or howling softly
- Opening their eyes partially or fully
- Breathing heavily or irregularly
All of this is normal. It looks wild, but it's just your dog processing their day through dreams. Maybe they're chasing squirrels. Maybe they're reliving that great belly rub. Who knows.
The important thing: don't wake them up during this phase unless absolutely necessary. Dogs can be disoriented and even snap if startled out of deep sleep. If they wake up on their own looking confused, just talk to them calmly until they reorient.
Light Sleep vs. Deep Sleep: The "One Eye Open" Mode
Dogs are natural light sleepers during the day. This comes from their ancestry—wild dogs needed to stay alert for predators even while resting.
When your dog is in this light sleep mode, they're not really fully asleep. They're resting, but their body stays ready to spring into action. You'll notice:
- Eyes partially open or opening frequently
- Ears twitching at sounds
- Body position that allows quick standing
- Instant alertness if something interesting happens
This isn't a medical concern—it's actually a sign of a healthy, alert dog. They're just doing what dogs do: resting while staying ready to investigate that suspicious noise from the kitchen.
When Open Eyes Signal a Problem: Lagophthalmos
Now let's talk about when you should actually worry.
If your dog can't fully close their eyes even when awake, that's a condition called lagophthalmos. This is different from normal partial-eye sleeping during rest—this is an inability to close the eyelids completely, ever.
What Causes Lagophthalmos?
Several things can prevent a dog from closing their eyes properly:
- Brachycephalic anatomy – Dogs with flat faces and prominent eyes (like Pugs, Bulldogs, Shih Tzus, and Boston Terriers) are more prone to this because their eye sockets are shallow
- Eyelid abnormalities – Congenital issues or injuries affecting eyelid structure
- Previous trauma or surgery – Scarring that prevents full closure
- Neurological conditions – Nerve damage affecting eyelid muscles
If you own a brachycephalic breed, it's especially important to monitor their eyes regularly. These dogs are already at higher risk for eye problems.
Why Lagophthalmos Is Serious
When the eye can't close completely, even a small exposed area causes problems:
- Corneal drying – The exposed portion dries out, causing discomfort and damage
- Corneal ulcers – Dry, unprotected cornea can develop painful ulcers
- Chronic irritation – Leading to redness, discharge, and pain
- Vision problems – Severe cases can affect sight permanently
If you notice your dog never fully closes their eyes—not just during sleep, but when blinking—schedule a vet appointment soon. This usually requires treatment, and in some cases, surgery.
Facial Paralysis: Another Cause to Know About
Sometimes a dog sleeps with one eye open (not both) because of facial nerve paralysis. This condition affects the muscles that control the eyelids on one side of the face.
Signs of Facial Paralysis
- Only one eye stays open or doesn't blink properly
- Drooping on one side of the face
- Difficulty eating or drinking on the affected side
- No blink reflex when you bring a finger close to the eye
What Causes It
Facial paralysis in dogs can result from:
- Middle or inner ear infections (otitis media/interna)
- Tumors affecting the facial nerve
- Trauma or injury to the head
- Idiopathic causes (no identifiable reason—similar to Bell's palsy in humans)
The eye complications are the same as with lagophthalmos: dryness, ulceration, and potential damage. Even if the dog produces tears normally, the inability to close the eye means those tears don't spread properly across the cornea.
Treatment depends on the underlying cause. Sometimes temporary surgical solutions protect the eye while vets work on diagnosing and treating the root problem.
Warning Signs That Need Veterinary Attention
So how do you know when your dog's open-eyed sleeping is normal versus a problem? Here's what to look for:
See a Vet If You Notice:
- Eye discharge – Especially yellow, green, or thick discharge
- Redness or inflammation – The white of the eye looks irritated
- Cloudiness or color changes – Any haziness in the eye
- Swelling around the eye – Puffy eyelids or surrounding tissue
- Pawing at the eye – Signs of discomfort or itching
- Squinting when awake – Difficulty keeping eyes open normally
- Hair loss around the eye – Could indicate chronic rubbing
- Inability to close eyes fully when blinking – Not just during sleep
- Only one eye affected – Asymmetry often signals a problem
If you see any of these signs, don't wait. Eye problems in dogs can progress quickly, and early treatment prevents serious damage.
What to Do If Your Dog Sleeps with Eyes Open
In most cases, you don't need to do anything. But here's a quick guide:
If It Seems Normal:
- Let your dog sleep—don't disturb them
- Observe occasionally to make sure eyes look healthy
- Keep their sleeping area clean and dust-free
- Make sure they have a comfortable, safe space to sleep deeply
If You're Concerned:
- Check their eyes when awake—do they close fully when blinking?
- Look for any discharge, redness, or cloudiness
- Watch for pawing, squinting, or signs of discomfort
- Note if only one eye is affected versus both
- Schedule a vet visit if anything seems off
For Brachycephalic Breeds:
- Monitor eyes more closely—these breeds are higher risk
- Consider regular eye checkups as part of routine care
- Keep eye drops (veterinarian-approved) on hand if recommended
- Watch for any changes in eye appearance or behavior
Frequently Asked Questions
Should I wake my dog if they're sleeping with eyes open?
No, let them sleep. Dogs naturally sleep with partially open eyes sometimes, especially during REM phases. Waking them can be startling and disorienting. Only wake them if something seems medically wrong.
Why does my dog's eye look white when sleeping?
You're seeing the third eyelid (nictitating membrane). This whitish membrane slides across the eye during sleep to protect and moisten it. It looks strange but is completely normal.
Is it normal for only one eye to be open during sleep?
Sometimes yes—dogs don't always relax both sides of their face equally. But if one eye consistently stays open even when awake and blinking, that could indicate facial paralysis and needs veterinary evaluation.
Do certain breeds sleep with their eyes open more often?
Yes. Brachycephalic breeds (Pugs, Bulldogs, Boston Terriers, Shih Tzus) with prominent eyes and shallow eye sockets are more likely to sleep with eyes partially open. They're also at higher risk for related eye problems.
My dog twitches and moves while sleeping with eyes open—is that a seizure?
Probably not. What you're describing sounds like normal REM sleep behavior. During this phase, dogs often twitch, vocalize, move their paws, and partially open their eyes. Seizures look different—they involve rigid muscles, uncontrolled shaking, and the dog won't respond normally when it stops. If you're unsure, record a video to show your vet.
Can sleeping with eyes open damage my dog's vision?
Normal partial-eye sleeping during rest won't cause damage—the third eyelid provides protection. However, if your dog has lagophthalmos (inability to close eyes fully) or facial paralysis, the chronic exposure can lead to corneal drying and ulcers that may affect vision.
Bottom Line
Seeing your dog sleep with their eyes open is usually nothing to worry about. It's a normal part of how dogs sleep, especially during lighter rest phases and REM cycles. Their third eyelid provides protection even when their outer lids aren't fully closed.
The time to pay attention is when you notice other symptoms—discharge, redness, cloudiness, inability to close eyes when blinking, or signs affecting only one eye. These could indicate conditions like lagophthalmos or facial paralysis that need veterinary care.
For most dogs, though? They're just sleeping in their own weird, wonderful, dog way. And honestly, watching them dream with eyes half-open and paws twitching is one of the funnier parts of living with a dog.
Let them rest. They're probably chasing something good.