The essentials
- Dogs see light and movement far better than humans — Dogs have more cells called rods in the retina (back of their eye) that are primarily responsible for vision in low-light conditions.
- Canine eyes have adaptations for improved night vision — Most dogs have a reflective layer on their eye called a tapetum lucidum, which magnifies incoming light.
- Dogs don’t distinguish details or colors as well as humans — Contrary to popular belief, however, most dogs aren’t completely colorblind.
For most people, the term “night vision” conjures images of high-tech night-vision goggles. Unfortunately, dogs don’t have that awesome ability to see in pitch black or total darkness. They can, however, see much better than humans in low-light situations.
Although dog and human eyes share many similarities, canine eyes have several features that help them see better at night. Learning how a dog’s eye works can help owners better understand their pet’s sight capabilities in different circumstances.
Anatomy of a dog’s eye
Anatomy of a dog’s eye. Image courtesy of Merck Veterinary Manual
Ophthalmology can be a tricky topic, with many scientific names to decipher. In truth, dog eyes are quite similar to human eyes in several ways. Knowing how to recognize each individual part of the eye can help owners better identify when something seems wrong or out of place.
- Orbit. This is the bone cavity or “eye socket” which holds the eyeball. It contains muscles, nerves, blood vessels, and tear ducts.
- Sclera. The sclera is the white outer surface of the eye.
- Conjunctiva. This thin mucous membrane lines the eyelids and covers the sclera.
- Cornea. The cornea is the clear outer layer of the eye. It both protects the eye and helps focus incoming light to the retina.
- Iris. The round, colored part of a dog’s eye. The iris can make the pupil larger or smaller, controlling the amount of light entering the eye.
- Pupil. The small dark area in the center of the eye. In low-light situations, the pupil will enlarge to let more light in. Conversely, it will contract under bright light.
- Lens. Found behind the iris, the lens changes its shape to allow light into the retina. Ciliary muscles in the eye either contact or relax to help the lens focus on nearby or distant objects.
- Retina. Important to a dog’s vision, the retina is the light-sensitive layer at the back of the eye. It contains photoreceptor cells (rods and cones) that sense light and convert it to electrical signals.
- Optic nerve. The bundle of nerve fibers known as the optic nerve is the bridge between the eye and the brain. Images from the photoreceptors are converted into electrical impulses, which are then carried to the brain by the optic nerve.
- Nictitating membrane. Dogs have a third eyelid located in the inner corner of the eye. It helps protect the cornea and distribute tears.
- Tapetum lucidum. This additional reflective layer enhances night vision by reflecting light back to the retina.
Here’s how dogs see in the dark
While dog’s eyes are similar to ours in form and function, there are several key differentiators that give our furry friends an edge, especially at night.
More rods than cones
In both humans and dogs, the retina of the eyes contains photoreceptor cells, which respond to light. These cells are called rods and cones. Generally, rods function in collecting dim light, while cones are responsible for color vision.
In canines, the retina consists mainly of rods with fewer cones. The result is a dog’s improved vision at night or in low lighting, but a diminished ability to differentiate colors and fine details.
Larger pupil size
Dogs have pupils that are relatively larger than ours. Their larger pupils allow them to take in more light, which helps them see well even in dimly lit conditions.
Tapetum lucidum
Another factor responsible for our pups’ superior night vision is the tapetum lucidum. This reflective layer is located behind the retina and aids in magnifying light. When light hits the tapetum lucidum, it bounces back to the retina, giving the photoreceptors a second chance to absorb it. This is the reason why many dogs’ eyes shine at night. But some dogs, especially those with blue eyes, may not have a tapetum at all. Commonly, dogs with no tapetum will appear to have red eyes in photos due to the visualization of the eye’s blood vessels.
👉 Other animals, such as cats, may also have a tapetum lucidum. This is why their eyes often glow in the dark.
Can dogs see color?
A commonly held misconception is that all dogs are colorblind. But dogs can see color, just not as well as humans. Dating back to the evolution from wild wolves, dogs developed larger lens and corneal surfaces, plus the tapetum membrane discussed above. The purpose was to improve night vision for hunting in the dark. To this end, dogs also developed more rod photoreceptors than cones, which help improve low-light vision in the retina. One result of this, however, was the presence of fewer cone receptors, responsible for color vision.
Dogs are considered dichromatic, meaning they only have two types of cones, while most humans have three. For this reason, many dogs view the world in a similar way as people with red-green colorblindness. This means they can’t easily tell the difference between red and green. But, they can see blue and yellow well.
Dog breeds and vision
While most dogs likely experience similar abilities to see, some dog breeds may have better vision than others. For example, sighthounds like the Basenji boast panoramic vision that’s especially accurate in low-light conditions.
Conversely, some dog breeds are more likely to develop cataracts and other eye problems than the canine population as a whole. Poodles, cocker spaniels, and labrador retrievers fall into this category. Age and other health conditions can also affect your dog’s eyesight, regardless of their breed.
Can dogs see better than cats at night?
Cats are crepuscular creatures who are much better at seeing in the dark than dogs. Their excellent ability to see in low-light situations helps their natural tendency to hunt around sunrise and sunset. However, dogs can likely see more colors than cats.
Nighttime safety tips
Even though dogs can see relatively well in the dark, they still don’t have perfect vision. Most importantly, if your dog is walking outside at night, there’s a good chance that humans won’t be able to see them. Follow these nighttime safety tips to keep your dog safe in the dark.
- Use a reflective collar or harness. If your dog goes outside at night, make sure they have a reflective harness or collar so humans can see them. This is especially important if you live in the country because dogs can be mistaken for wildlife in low-light conditions.
- Keep them on-leash. Depending on where you live, you might let your dog off-leash during the daytime. However, you should keep your dog on a leash or in a fenced area at night so they won’t get hit by a car or mistaken for another animal.
- Plug in a night light. Most dogs will do just fine without additional lighting at night. However, just like in humans, most dogs’ vision worsens with age. Geriatric dogs with lenticular sclerosis often struggle with night vision, so a night light could be helpful in these cases.
If you find your dog takes the lead in nighttime walks, it could be because their night vision is better than yours. Even so, it’s important to keep them safe at night by putting them in a reflective harness and only walking them on a leash. If you have a senior dog or live in an especially dark house, you might also consider plugging in a night light to help them get around when the lights are off.
Be a smarter pet parent
Sign up for the best pet advice you can get
Frequently asked questions
Do dogs have night vision?
While dogs can’t see in total darkness, they do have much better night vision than humans. This is due to their rod photoreceptors and a light-reflecting layer called the tapetum lucidum.
Are dogs afraid of the dark?
Most dogs have adapted well to low-light situations. Some, however, like those with eye diseases or those going blind, may experience some challenges in darkness. Generally, dogs should have no reason to fear the darkness alone.
Is it okay for dogs to be in the dark alone?
You might feel bad about leaving your dog in the dark, but they likely don’t mind. Many dogs are fine with natural light, even at night, but you can consider a small night light if your home is especially dark, or if your dog is geriatric.
Do dogs need a light on at night?
Most dogs should be able to see fine without any lights on because their night vision is better than ours. However, if you have an older dog with eye problems or live in an especially dark house, you might want to plug in a night light for them.
Can dogs see better in the dark than light?
Dogs can see better at night than humans can, but humans have better day-time vision. However, dogs don’t necessarily see better at night than during the day.
