Why Do Some Dogs Sleep With Their Eyes Open?

Have you ever looked over at your dog during a nap and thought, “Are they… awake?!”
Watching a dog sleep with their eyes half-open can be unsettling, but it’s actually more common than most pet owners realize.

And here’s the interesting part: this quirky behavior has a purpose.

It’s a Built-In Survival Instinct

Dogs may be cuddly companions today, but their instincts still run deep.
Sleeping with their eyes slightly open helps them stay alert to sudden movement, sounds, or changes around them. It’s the canine version of “light sleeping.”

Your Dog Might Be Dreaming

During REM sleep—the dream stage—dogs twitch, paddle their paws, and sometimes their eyes partially open.
If you see their nose wiggling or paws “running,” they’re probably dreaming about something fun or exciting.

Brachycephalic Breeds Struggle to Fully Close Their Eyes

Short-snout breeds like Bulldogs, Pugs, and Shih Tzus sometimes can’t close their eyelids completely due to their facial structure.
It looks strange, but for many of them, it’s normal.

Older Dogs Do It More Often

As dogs age, facial muscle tone changes. Their eyelids may relax, making it harder to fully close their eyes during deep sleep.
If it’s paired with redness or irritation, though, it’s worth mentioning to your vet.

When It Might Be a Concern

Most of the time, it’s harmless.
But if your dog suddenly starts sleeping with their eyes unusually wide open, or you notice dryness, squinting when awake, or discharge, they may need a quick checkup.

Final Thoughts

Dogs sleep in all kinds of weird and wonderful ways—and half-open eyes are usually just another quirky canine habit.
As long as they’re comfortable, relaxed, and acting normally when awake, there’s nothing to worry about.

⚠️ Disclaimer: This is not professional veterinary advice.