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The Surprising Reason Dogs Sometimes Sleep With Their Eyes Open

By: Ejay Camposano
A college graduate with a degree in Electrical Engineering, Ejay has a diverse background that combines technical expertise with a passion for pets and is now one of the content writers at IHD. Read more
| October 3, 2024

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If you’ve ever seen your dog sleeping with their eyes open, you might wonder if it’s normal. While it can be a bit unsettling to watch your furry friend snoozing while appearing to stare off into space, this behavior is perfectly natural for many dogs. Although it may seem odd, dogs have several reasons for keeping their eyes partially or fully open while sleeping. Various factors are at play, from evolutionary instincts to physical traits, and most of the time, it’s nothing to worry about.

Evolutionary Survival Instincts

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Dogs are descendants of wild animals that had to remain alert to survive in dangerous environments. Sleeping with their eyes open could be a remnant of this survival instinct. In the wild, keeping their eyes slightly open while resting allowed animals to appear more alert, deterring potential predators. Even though your dog might be safely snuggled up on a cozy couch, this instinct may still kick in. It’s a way of staying “on guard” even during nap time, giving them an edge should something unexpected happen.

Light Sleep Phase

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Dogs, like humans, have different sleep phases, including light and deep sleep. During the light sleep phase, your dog may not be fully unconscious and might keep their eyes open to some extent. In this state, they are still aware of their surroundings and may respond quickly to external stimuli. If your dog is napping with one eye open, they could simply be in the light phase of sleep, where they remain semi-conscious, just in case something interesting happens that requires their attention.

REM Sleep and Dreaming

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One fascinating reason dogs sleep with their eyes open is related to the REM (Rapid Eye Movement) phase of sleep, which is when dogs dream. During REM sleep, dogs can exhibit various physical behaviors, including twitching, moving their legs, and making sounds. Sometimes, their eyes may open slightly, though they’re still in a deep sleep. This can be particularly common in dogs who are dreaming, as their bodies react to their dreams, causing slight eye movements or even partially open eyelids.

Brachycephalic Breeds and Shallow Eye Sockets

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Certain breeds of dogs, especially brachycephalic breeds like Bulldogs, Pugs, and Boston Terriers, are more prone to sleeping with their eyes open due to the structure of their skulls. These dogs have shallow eye sockets, which can cause their eyelids not to fully close while they sleep. It’s common for these breeds to be seen with their eyes half-open during rest simply because their anatomy makes it difficult for their eyes to close completely. While it may look unusual, it’s normal for these dogs.

Protective Behavior

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Dogs are naturally protective creatures, especially in their homes and families. Some dogs may sleep with their eyes open as part of their protective instinct. By keeping their eyes partially open, they can stay visually aware of their environment, making it easier to wake up and respond quickly to potential threats. Guard dog breeds, in particular, may exhibit this behavior more frequently, as their instincts to protect are more finely tuned. It’s their way of watching the situation while still catching some rest.

Dry Eye Syndrome (Keratoconjunctivitis Sicca)

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Sometimes, sleeping with their eyes open can indicate an underlying health issue like dry eye syndrome, also known as keratoconjunctivitis sicca. This condition occurs when a dog’s eyes do not produce enough tears to keep them lubricated. As a result, the eyelids may not close completely during sleep, and the dog may appear to be resting with their eyes open. If you notice that your dog’s eyes look dry, red, or irritated when they sleep this way, it’s a good idea to consult a veterinarian to rule out any medical concerns.

Habit from Puppyhood

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Many dogs develop the habit of sleeping with their eyes open from an early age. Puppies often sleep with their eyes partially open, especially during their first few weeks of life. This could be because they are still developing their muscle control and neurological functions, including the ability to close their eyes fully during sleep. Some dogs simply carry this habit into adulthood, and while it might look strange, it’s usually harmless. It’s just one of those quirks that makes dogs so unique.

Dreaming of a Midnight Snack

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First, dogs love food, and some might even dream about it. While it’s a humorous thought, a dog sleeping with their eyes open might be in the middle of a dream about chasing a squirrel or sniffing out a tasty treat. Their partial wakefulness and slight eye movements could mean they’re fully immersed in an exciting dream, and their body responds to what’s happening in their mind. It’s not unusual for dogs to dream with their eyes open, adding to their already endearing, quirky behaviors.

Senior Dogs and Cognitive Changes

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As dogs age, they can experience cognitive changes that affect their sleep patterns. Older dogs are more likely to sleep with their eyes open due to shifts in brain function or muscle control. Senior dogs may also enter a lighter sleep state more frequently, which can cause them to rest with their eyes partially open. This behavior might increase as your dog gets older. Still, it’s usually just a part of the aging process and isn’t necessarily a cause for concern unless accompanied by other symptoms of cognitive decline.

Doggie Zoning Out

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Sometimes, dogs simply zone out while relaxing, drifting into a semi-sleep state while still maintaining some awareness of their environment. You might notice your dog resting with their eyes open as they sit on the couch, half-awake and half-asleep, as if they’re in a trance. This “zoning out” behavior can happen when dogs are particularly relaxed but not fully asleep. It’s like when humans daydream or doze off while watching TV—your dog is enjoying some downtime without fully committing to sleep.

Dog’s Sleep Habits Are Always Full Of Surprises

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Just when you think you’ve seen all the quirky things your dog can do, they surprise you by sleeping with their eyes open! This unusual behavior is another aspect of what makes dogs so endlessly fascinating. From evolutionary instincts to light sleep phases, there’s always a reason behind their curious actions. So, the next time you catch your dog in a half-open-eyed nap, remember—there’s always more than meets the eye when it comes to our four-legged friends’ mysterious and adorable habits!