A dog’s sight is highly important for his activities. Even if dogs don’t possess a sight that is as developed as in humans, they are not color blind. Color blindness in dogs is a mistaken belief; dogs just see colors differently. If you are a dog owner, it helps to know how your pet sees the world in comparison with what humans can see, so that you can use this while training or relating to your dog.
How Dogs See Colors
Even though dogs are not color blind as many people think, they see colors differently. Dogs don’t have the chromatic acuity of humans, who can see millions of colors.
The dog’s eyes have a lower number of cone cells in the retina than humans, and this significantly reduces the number of colors they perceive. The cone cells are the ones that regulate the color detection in dogs and humans. People have a number of cone cells in the retina about 7 times higher than dogs.
Canines can only see two primary colors: blue and yellow, so they have a dichromatic vision. Humans have a trichromatic vision, being able to see all primary colors: red, blue and yellow and a lot of other colors in between. Instead of red, dogs see a color that is comparable to a brown or sepia shade, which means that dogs are not entirely color blind. Dogs perceive the colors yellow, orange and red in very similar way. Dogs can also see whites, blues, purples and a lot of shades of grey.
Dogs have one main advantage over human sight: they can see better in low light conditions. This is due to a higher number of rod cells, which are photoreceptors that regulate the perception of black and whites. This means that dogs have a better night vision, comparable to the keen night vision of felines. The improved night vision is also due to an additional membrane of the eyes which helps dogs to receive light.
Field of Vision
The dog’s field of vision varies according to the size and shape of the dog’s skull, being between 200 and 270 degrees, while humans have a field of vision of 180 degrees.
Dogs may also have issues in appreciating depth, even if the dog’s field of vision is a lot broader than the human vision. The anatomy of a dog’s eye is similar to the human eye, but the ocular globes of canines have less movement.
Dogs are farsighted and are able to detect moving objects more easily than objects that are immobile.
They can see laterally, while the sight of humans is both binocular and forward. For this reason, dogs will greatly rely on their reflexes when detecting movement, and less on their vision. Dogs have the advantage of seeing movement behind them, while humans can’t.
All in all, humans have a better vision than dogs, but dogs are not color blind. They can see blue and yellow and a lot of shades between these. Their vision is not as developed as the human vision, but dogs have excellent night vision.