As a dog owner, you may have heard that dogs see only in black and white. In other words, they are color blind.
Turns out this is not quite the case.
The idea that dogs are colorblind was broadly accepted for many years, due largely to the influence of Will Judy, writer and publisher of Dog Week Magazine. He authored a popular canine training manual, Training the Dog, published in 1937. In the manual he wrote, “It’s likely that all the external world appears to them as varying highlights of black and gray.”
In the decades since Mr. Judy’s book was published, a lot of research has been done on dog vision. Dogs are not completely colorblind but they do perceive color differently than humans.
The dog’s ancestors developed their vision primarily to be used at night, in low light situations, where they tracked and hunted their prey. So being able to see different colors was not as important as being able to discern movement and being able to see in near darkness.
In the retina of the eye, in both dogs and humans are specialized types of cells that have different functions: rods which are sensitive in low light and can sense movement and cones, which are sensitive in bright light and perceive color.
People have more cones in their retinas than dogs do, which makes us better at seeing colors. Also, humans and some other primates are what is known as trichromatic, meaning we have three different types of cones. Dogs have only two types and are dichromatic.
Each specific type of cone functions to register different wavelengths of light. We can see the color of a bouquet of red roses or the green in Irish shamrocks due to these cones that are specialized for red and green. People who suffer from color blindness often are missing these red-green cones, just like dogs.
It’s interesting that the most popular color for dog toys is red or orange, because those are precisely the colors that dogs have the most trouble seeing! Dogs are best at seeing yellow or blue objects.
If you would like to see an object or a scene approximately the way your dog sees it, there is a cool website called Dog Vision where you can upload an image that will let you see through your dog’s eyes.
In the meantime, replace that red or orange ball and frisbee with yellow or blue!