Do Dogs Have Night Vision?

If you've ever noticed how well your dog can find their way around in the dark, you might wonder, "Do dogs have night vision?" The short answer is yes, dogs can see in the dark. However, dog night vision is much different than when someone wears night vision goggles in the movies. Dogs evolved from wild dogs and wolves, which are crepuscular and most active during dusk and dawn. For this reason, your dog's eyes can see better at night and in low light than yours. 

• Canine Eye Structure
• Dog Vision Vs. Human Vision
• How Do Dogs See At Night?
• Why Do Dogs Have Eyes That Glow In The Dark?
• Common Canine Vision Issues
• Do Dogs Have Night Vision?: FAQs
• Final Notes

Canine Eye Structure

Dog and human eyes are similar, except they differ in a few key ways that make dogs able to see better in the dark. It's also the reason why they see color differently than you do. The eye constantly adjusts the amount of light it lets in and focuses on objects to produce images in the brain.¹ Ultimately, different parts of the eye work together to help your dog see at night. Components of the eye that focus light include:

• Cornea: A clear layer over the eye's surface, the cornea is responsible for protecting the eye and letting light in. 
• Iris: The iris is circular and colored. It is responsible for adjusting the size of the pupil to control how much light is let into the eye. 
• Pupil: The pupil is the center of the eye. You may notice dogs have large pupils, which enlarge to let more light in when it's dark. 
• Lens: The lens changes shape to focus light onto the retina. 
• Retina: The retina contains light-sensing cells called photoreceptors.¹ These photoreceptors, also known as cones and rods, convert light into electrical signals that are sent to the dog’s brain, controlling how dogs see colors and in low light. 

Dog Vision Vs. Human Vision

Dogs have a different number of cones and rods than humans. Rods are responsible for collecting light, while cones are responsible for detecting color. They have fewer cones and more rods, resulting in better night vision and color blindness.² It's important to note that by color blindness, we mean that dogs can see certain colors but not others; dogs are red-green color blind but do not see in blacks and grays. Dogs see color differently than you do because humans have more cones and fewer rods. Since dogs have more rods, they can see better at night and in the dark. 

Dogs also have less depth perception and visual acuity than humans. However, they have better motion detection, which is why they're such good hunters.² Is a dog's vision better than a human's? Not necessarily. For example, dogs see movement better and can see in the dark. However, human eyes detect more colors and have better depth perception. 

How Do Dogs See At Night?

Can dogs see in the dark? They absolutely can, but that doesn't mean they have perfect night vision. They can't see in total darkness because their eyes rely on at least some light to see. Remember, there are some ways in which your vision is better than your dog's. However, dogs can see better at night as long as enough light can be reflected into the retina. Here are a few reasons why dogs can see at night: 

Photoreceptors

Your dog's ability to see in the dark is due to the large number of rods in their eyes, which collect dim light. Since they have more of these light-sensitive rods than humans, they have better night vision.³ Remember, the retina contains both rods and cones, which affect color and night vision. 

Tapetum Lucidum

While rods are responsible for helping your dog see in low light, their ability to see so well in the dark is due to the tapetum lucidum, a reflective layer of cells behind the dog's retina that's used to magnify incoming light.³ The tapetum lucidum helps dogs use light more efficiently, helping the retina register it. It reflects more light and enables dogs to use less light to see.⁴ Therefore, the photoreceptors in the retina have more than one opportunity to capture light, as the tapetum lucidum magnifies dim light and increases their ability to see objects in the dark.²

Pupil Size

Dogs have larger pupils than humans. The pupil, which is responsible for determining how much light is let into the eye, can dilate and constrict, and the larger the pupil, the more light can enter the eye, allowing dogs to see better at night.⁴ 

Threshold For Clicker Fusion

Dogs also have higher critical flicker fusion frequency (CFF) than humans. CFF is the frequency of flickering light that can be perceived. Ultimately, flashing lights can be distinguished by humans, but as the flashing frequency increases, it affects vision.⁵ Dogs have a higher CFF level than humans, so when watching television, they likely only see flickering lights instead of objects moving on a screen. However, they have a higher threshold for clicker fusion (TFF) to help them detect movements in the dark.⁶

Other Senses

Dogs use their other senses to help them see. While they have good night vision, they rely on their senses of hearing and smell to help them make their way through their environments. Your dog has a powerful sense of smell that can help them determine which room they're in or follow scents throughout the home. In addition, they can hear things you can't, making it easier to locate sounds like your voice when you call their names in the middle of the night. 

Why Do Dogs Have Eyes That Glow In The Dark?

The same part of the eye that allows your dog to see better in the dark causes their eyes to glow. The tapetum lucidum is highly reflective and can cause glinting and glowing in the dark because it reflects light.³ This blue or green glinting can also occur during the day whenever light shines into your dog's eyes, which is why their eyes glow when you use the flash on your camera. 

Common Canine Vision Issues

Dog night vision can be affected by various vision issues. Good eye care is essential for dogs because eye health can impact their vision. Dogs with vision problems are at an increased risk of finding danger because they can't see their way around their environments. For example, blind dogs may walk into objects until they learn their way around their home. Of course, dogs use their other senses, like smell and hearing, to help them interact with their environment, but they rely on their eyes. Knowing common canine vision issues can help you get your dog the help they need to prevent potential dog blindness later in life. 

Cherry Eye

Cherry eye is a condition in which the tear gland in the lower corner of the dog's eye becomes inflamed and eventually prolapses. It typically occurs in young dogs and may occur during vision development in puppies, but it can happen to any dog at any age. It's also more common in certain breeds. The tear gland can swell up, but it's not painful for most dogs. However, eventually, the gland can become so swollen that it prevents the eyelid from fully closing, which can cause dryness and irritation that leads to pain. Cherry eye can lead to blindness, but if it's treated and doesn't become infected, a dog should be able to see fairly well, depending on the size of the inflamed gland. However, left untreated, cherry eye can severely impair your dog’s ability to see.

Glaucoma

Glaucoma is another canine vision issue that can lead to blindness and occurs when there's an imbalance in fluid production and drainage, resulting in fluid buildup and eye pressure that destroys the retina.⁷ There are two types of glaucoma in dogs: open and closed-angle glaucoma. Open-angle glaucoma is painless and typically occurs over a long period of time. However, closed-angle glaucoma is sudden and causes severe pain and vision loss.⁷ 

Glaucoma in dogs causes dilated pupils that don't respond to light, redness, swelling, and sudden blindness.⁷ Pet parents often notice a cloudy appearance in their dog's eyes. Glaucoma in dogs is very serious because it can impact their vision quickly, so you should take your dog to the vet as soon as possible if you notice any of the symptoms. Your vet will aim to reduce the risk of blindness with treatments that include medicated eye drops and pain medications. Serious cases of glaucoma in dogs may result in removing the eye to reduce pain.⁷ 

Cataracts

Cataracts are another eye disease that affects humans and dogs. Cataracts occur when the lens becomes cloudy and blocks light from reaching the retina, impacting your dog's ability to see.⁸ Cataracts in dogs can be present at birth or develop over time. Cataracts are inherited, but other causes can include inflammation, eye trauma, diabetes, and malnutrition.⁸ When left untreated, cataracts can cause blindness in dogs because it blocks the light from entering the lens to see objects. In addition, cataracts can cause glaucoma, damaging the optic nerve and causing permanent blindness. Unfortunately, there are currently no non-surgical methods for treating cataracts, so dogs that develop cataracts will need surgery to remove them and restore vision. 

Corneal Ulcers

Corneal ulcers in dogs occur when there is damage to the clear covering of the eye. The defect in the cornea is referred to as an ulcer because the cornea is composed of 3 layers: the superficial, deep, and basement membrane. Ulcers can cause the corneal membrane to protrude or even cause a hole in the cornea.⁹ Most corneal ulcers are caused by injuries, including damage caused when your dog scratches their eye, foreign objects, and chemicals. A corneal ulcer is painful and can cause infection. Severe corneal ulcers can lead to the eye rupturing if left untreated.  Ulcers are typically treated with antibiotic drops, but surgery may be required to allow for normal healing and remove layers of the affected tissue.⁹

Do Dogs Have Night Vision?: FAQs

Do dogs have good vision?

Dogs with healthy eyes have good vision, but their vision differs greatly from yours. For example, because they have more rods, they can see well in the dark and have better motion visibility. However, they don't see the same colors as you do and may not see objects as clearly. 

Can dogs see colors?

Yes, dogs can see some colors. However, dogs are red-green colorblind because they have fewer cones than humans, so they see colors differently. Dogs can see blues and yellows very well. However, they may be unable to detect red or green. Because of this, dogs have poorer vision than humans, and some colors may blend together, making it difficult for them to find certain objects. 

Do dogs have better night vision than cats?

Can cats see in the dark? Absolutely, and they're better at it than dogs. Cats are more sensitive to light than dogs, so they can see better at night. In addition, cats have a tapetum lucidum that's more effective than a dog's, and their split pupils allow more light to enter the eye to help them see better in the dark. 

Should you leave a light on for your dog at night?

Your dog cannot see in total darkness because they need at least some light for the rods in the eyes to work properly. Therefore, you should leave a light on for your dog if they like to wander around the house at night. Keeping a nightlight on in your home is a good way to help them see better at night, but even in total darkness, dogs can rely on their other senses to help them get around. 

Final Notes

Can dogs see at night? Yes, but they can't see in total darkness. Dogs have great night vision, but their ability to see at night depends on having some light available, whether it's from a nightlight or a light outside. While your dog has many powerful senses, they rely on their sense of sight every day to get around and explore their environments, so it's important to care for their eye health. 

As dogs get older, they're more prone to blindness and various eye diseases, but you can help your dog and protect their vision by discussing signs of eye problems with a vet. Consult a Dutch vet if you notice signs of eye or vision issues in your dog. Dutch offers telemedicine for pets to help you care for your dog's eye health and vision from the comfort of your own home. Sign up for Dutch today.