It is a well-known fact that dogs have excellent senses of smell and good hearing. But how good is a dog’s vision? Do dogs have good eyesight? The answer to that question is not really. Objectively, dogs have bad eyesight, especially when compared to humans. However, the truth is more complicated and deeper than at first glance. Dogs might have bad eyesight compared to humanity’s best but that doesn’t mean that their eyesight is ineffective or bad for dogs.
Here are some excellent facts and figures about dogs’ vision that will help you understand how dogs see the world and why they are built the way they are.
The 4 Facts About Dog Eyesight:
Dogs are fairly nearsighted. The typical dog has a visual acuity score of 20/75.1 This means that dogs must be much closer to an object to make it out in the same detail as a person. A dog must be standing 20 feet from an object to make out the same detail that a human can make out at a 75-foot distance. That means that dogs are good at seeing things up close but struggle to make out details of distant objects. That doesn’t necessarily mean that dogs have poor eyesight. They just have different eyesight. Dogs’ eyes are much better at other things compared to humans.
2. Night Vision
Dogs are crepuscular hunters. That means that they prefer to hunt at twilight when the light is getting low, but it has not yet reached full darkness. This behavior is what causes coyotes to come out around sunset and why wolves are found howling at the moon. When there is a bright moon, it gives dogs just enough light to become extremely effective hunters. This helps dogs compensate for their poor visual acuity by making them able to see better than other animals during twilight hours. This helps bridge the gap between dogs and humans and other animals that dogs might be interested in hunting.
3. Superior Movement Detection
Another thing that dogs have going for them over other animals is their ability to detect motion. Dogs have very good motion detection. Even if they cannot make out the details of something moving far away, they can tell that something is moving. Humans, by comparison, have rather poor motion detection. Dogs can detect minute movements from a distance and hone in on the exact location of the movement. This helps them zero in on things that they smell and hear without needing to see exactly what it is that is moving.
4. Color Impaired
For a long time, many people believed that dogs were colorblind or had monochromatic vision. Now we know that that is not exactly true. Dogs have fewer color detecting cells in their eyes, so they see fewer colors. The colors that they do see are also more muted than what people see, but they absolutely see color. It is impossible to know exactly what dogs see but using specific vision tests and detailed examinations of the structures of the eye we can get a pretty good guess. Dogs can see three colors very well: blue, yellow, and gray. The rest of the colors are extremely muted or impossible for dogs to see.
Do Dogs Have Bad Eyesight?
If a person were diagnosed with a dog’s vision, they would likely be flagged as someone with a serious medical problem. Extremely nearsighted, unable to see a large range of colors, and having no true night vision might sound like an animal with bad vision, but the truth is that dogs just have different vision. Dogs do not need to have eyesight as good as humans or other animals because they have extremely good senses of hearing and smell. Humans need good eyesight because their other senses are relatively poor. A dog’s eyesight compliments their hearing and smell but does not need to be the best sense that they possess.
Canine Vision Compared
How good is a dog’s eyesight compared to other animals? The answer is not great. If we are simply comparing vision and visual acuity, dogs actually have very poor eyesight. The only other animal that has worse visual acuity than dogs are cats, and they make up for that by having very good night vision. Even horses have better vision than dogs, and horses are able to see in a radius that is nearly a full 360 degrees.
Animals with sharp visual acuity include hunting birds like eagles, hawks, and falcons. Predatory fish, like sharks, also have a surprising amount of visual acuity.
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Dogs have relatively poor eyesight compared to some other animals, but it does not hamper their ability to live and function as it does for humans. Dogs have exceptional movement detection and great twilight vision, which helps make up for their low visual acuity and poor color vision. A dog’s eyesight works to complement their senses of smell and hearing rather than serve as the primary way that they interact with the world.
Featured Image Credit: Kerrie T, Shutterstock