Why does my dog sleep with his eyes open?

If you’ve ever watched your dog doze with one or both eyes partly open, it can spark anything from gentle curiosity to real concern—especially if you’re a new owner, caring for a puppy, or looking after a senior dog. Noticing this behavior matters because it’s one of those visible signs that can help you tell normal sleeping patterns apart from something that needs veterinary attention; understanding what’s typical reduces worry and helps you act quickly when it isn’t.

Short take — is it normal when your dog sleeps with his eyes open?

Most of the time a dog sleeping with eyes open is harmless: dogs may sleep with partially open eyelids during light sleep or REM when facial muscles relax, and the third eyelid may protect the eye; in fewer cases it may suggest an eye surface problem or a neurological issue and should be checked if other worrying signs appear.

When the behavior is routine—short episodes during dream phases, no discharge, and no change in vision—it’s usually normal. If the eyes look sore, are stuck open, or the dog shows changes in coordination or alertness, that’s when prompt evaluation is sensible.

What’s happening biologically: the anatomy and sleep stages behind open-eyed naps

Dogs go through sleep cycles similar to humans, including REM (rapid eye movement) and non-REM stages, and eyelid control changes across those phases. During light sleep or REM, facial and eyelid muscles relax so the lids may not close fully; the result can be a glazed or partly open appearance without meaning the dog is awake.

There’s a third eyelid, the nictitating membrane, tucked at the inner corner of the eye that can slide across the surface to keep the cornea moist and protected. When the lids don’t fully shut the third eyelid may be more visible or move more, which often prevents injury and dries less of the cornea.

Reflexes that normally close the eyelid—the palpebral reflex and orbicularis oculi muscle tone—are under both local control and broader autonomic and brainstem influence. During deeper stages of sleep or under certain medications these reflexes may be reduced, making partial eye opening more likely. I typically see this in relaxed dogs that otherwise have normal eye appearance and behavior.

When it occurs: common triggers, breed and age differences, and situational factors

Timing and sleep depth matter. You’re most likely to notice partially open eyes during daytime naps and especially during REM phases at night when dogs twitch, make noise, or move their paws. In deep non-REM sleep the lids are more likely to be fully closed, while lighter sleep can leave lids relaxed and open.

Breed and facial anatomy can make the phenomenon more obvious. Dogs with shallow eye sockets, wide palpebral fissures, or loose eyelid conformation—common in some brachycephalic and toy breeds—may look like they sleep with eyes open more often because their lids naturally cover less of the eyeball.

Age, fatigue, medications, and illness influence eyelid control: puppies with immature neuromuscular control, older dogs with reduced muscle tone or neurological disease, and animals on sedatives or certain pain medications may show more frequent partial eye opening. Environmental factors—bright light, drafts, or sudden noises—can also produce brief arousal or partial eyelid opening during sleep.

Warning signs to watch for — when open-eyed sleeping means it’s time to see a vet

• Persistent or worsening eye discharge, redness, swelling, or a smelly eye—these can point to infection, inflammation, or blocked tear drainage that should be examined.
• If an eye appears stuck open, shows a cloudy or dull corneal surface, or you spot a raw area on the cornea (which may make the eye water or the dog blink excessively), suspect corneal injury and seek care to avoid long-term damage.
• Any concurrent neurological signs—new stumbling, circling, head tilt, seizures, or sudden changes in responsiveness—may suggest a brain or nerve problem rather than a simple sleep quirk and deserve urgent evaluation.
• A sudden change in how often your dog sleeps with eyes open, or associated changes in appetite, activity, or vision, is another reason to contact your veterinarian rather than assuming it’s benign.

Owner checklist: immediate steps and follow-ups if your dog sleeps with eyes open

Observe calmly and gather information. Note when the behavior started, whether it’s getting worse, how often it happens, and any other changes in behavior or appetite. I recommend videoing episodes if possible—short clips made on a phone are extremely helpful to a veterinarian because they show context and timing.

Do a gentle check without forcing the eyelid. If your dog allows, look for obvious discharge, cloudiness, or a foreign body at the corner of the eye. Don’t prod the eyeball, attempt to remove embedded objects yourself, or apply over-the-counter medications unless instructed by your vet.

Keep a simple timeline: dates and notes about frequency, whether the eye appears painful, any medications your dog is taking, and recent events like trauma, exposure to irritants, or new supplements. This record will speed up diagnosis when you call your veterinarian.

When you contact the clinic, describe what you’ve seen and send any videos. If the eye appears sore, the dog won’t blink, or you notice neurological signs, ask for an expedited appointment; eyes heal best with timely treatment and some problems can progress quickly.

Make the bedroom dog-friendly: environment tweaks and training tips to improve rest

Make your dog’s sleep area restful and predictable. A dim, draft-free corner with a supportive bed reduces startled awakenings that can make partial eye opening more noticeable. Consistent routines around bedtime also promote deeper sleep cycles.

Reduce nighttime disturbances that interrupt REM phases: minimize late-night loud noises, avoid abrupt handling while the dog is asleep, and keep lights low. If your dog sleeps near you, consider a low-level night light rather than a bright lamp so you can check without startling them.

Train your dog gradually to tolerate gentle handling of the head and face. Short, positive sessions where you touch the area around the eyes and reward calm behavior can make future veterinary exams and quick at-home checks much easier and less stressful for both of you.

Limit exposure to known eye irritants—smoke, aerosols, household cleaners, and dusty environments—especially for dogs with prominent eyes or known tear-film problems. A cleaner environment reduces the chance of surface irritation that might make eyes water or look abnormal during sleep.

Helpful gear: bedding, lighting and calming tools that reduce restless sleep

• Pet camera: A basic indoor pet camera with night vision lets you record sleep episodes without disturbing your dog and provides clear clips to share with your vet.
• Comfortable enclosed bed or high-sided bed: Beds that reduce drafts and limit direct light can help your dog sleep more deeply and protect the eyes from debris and airflow.
• Sterile saline solution (veterinary grade) kept in the house: Used only to flush away non-embedded debris and only under your veterinarian’s guidance; avoid using human antibiotic drops or other medications without advice.
• Low-intensity night-light: Provides enough illumination to observe your dog without fully waking them, and tends to be less startling than turning on a room light.

Sources and further reading — studies, vet guidance and trusted resources

• Merck Veterinary Manual: “Corneal Ulcers in Dogs” — Merck Veterinary Manual entry on recognition and treatment of corneal damage.
• American College of Veterinary Ophthalmologists (ACVO): “Client Information – The Third Eyelid (Nictitating Membrane)” — ACVO resources on ocular anatomy and common client concerns.
• Gelatt KN. Veterinary Ophthalmology, 6th Edition. Wiley-Blackwell — comprehensive textbook on eye anatomy, physiology, and disease in small animals.
• De Lahunta A, Glass E. Veterinary Neuroanatomy and Clinical Neurology, 4th Edition. Elsevier — for neuroanatomy and signs of central nervous system disease that can affect eyelid function.
• American Veterinary Medical Association (AVMA): “Caring for Your Older Dog” — client-focused guidance on age-related changes that can affect sleep and eye health.