Are Dogs Color Blind?

One of the mysteries surrounding dogs that often comes up for discussion at Pickle & Polly is whether dogs are color-blind or not. Does your pet see the world around them with the full spectrum of color that we do? Or do they view the world in varying shades of gray?

Hollywood would have us believe that canine vision is limited to dull greys and murky whites because that's how scenes from a dog's point of view are often portrayed. The concept of black-and-white vision in dogs was first professed by Will Judy, a lifelong dog enthusiast, writer, and past publisher of Dog Week magazine, who said that dogs were only able to perceive single tones and shades. As he put it in his 1937 "Training the Dog" manual.

Are dogs color blind, and if not, how do they see the world?

Can Dogs See Color?

The back of the human eye is covered with the retina, which holds millions of light-sensitive organisms called rods and cones. Rods are most active during low light conditions, while cones are activated by bright lights and colors. They all send electrical signals to the brain that translates into a visual representation of our world.

There are three types of cones, and each cone is sensitive to a particular wavelength of light. The wavelength determines the shades of color that we see. For example, when we view a bright yellow lemon, the red and green cones are activated. When you mix red and green together, you get yellow.

Color blindness in a human means one type of color-sensitive cone is defective. Because a dog's eye has only two types of cones, all types of dogs are technically color blind, at least from a human perspective.

However, when we look at how the canine eye evolved, we can get more of a sense of how they perceive the world. Before getting domesticated into the furry, friendly creatures we know and love today, ancient dogs were efficient nocturnal hunters. The physiology of a dog's eyes gives them an advantage when hunting in the dark. They are perfectly suited to making out shapes and detecting movement in low-light conditions.

Canine eyes possess a larger lens and corneal surface to take advantage of the fewer photons bouncing around at night. Their retina also contains more rods, which improves their low-light vision. Humans have fewer rods and more cones, which makes our vision more suited to brighter, daytime conditions.

Dogs may have fewer cones, but that doesn't mean they can't see colors. A regular human eye is tetrachromatic, while eyes with a defective cone are called dichromatic, which is similar to how a dog might see the world.

The two cones in a dog's eye are sensitive to the yellow and blue wavelengths, which is equivalent to a person with red-green color blindness. You can use this information to choose more appropriate and visually interesting doggy toys for your pet to play with.

If you and your dog enjoy games of fetch, don't buy a red ball, as they may lose sight of it in green grass. Go for toys made in blues and yellows, which your dog can more easily perceive.

It's possible to experiment with how your canine friend views the world with a downloadable dog simulator app for Android and iOS. Keep in mind that how the eye sees the world versus how the brain interprets the information are two different things. We may think we know how dogs see, but we can't know for sure how their brain processes this information. Still, it's an interesting experiment.