By Michael Litzky, CPDT-KA
There are a few facts that everyone knows about dogs. Their sense of smell is significantly better than our own. They bark. They have fur, which they sometimes shed. And of course, they don’t see color. Well, that last one isn’t true. Dogs are capable of seeing lots of different colors.
Most primates, including humans, have trichromatic color vision. We, like our chimpanzee cousins, have three different types of cells in our eyes that interpret color. These cells are called cones. You may remember learning about cones and rods in science class. Dogs and many other non-primate mammals have dichromatic color vision, with only two types of cones. While we may not be able to ask a dog what it’s like to see the world with dichromatic vision, there are some people we can ask. Over 4% of the population is color blind, most commonly as a result of having only two of the three types of cone. They too have dichromatic color vision. Does this mean they don’t see any color? Of course not. They’ll tell you they can see a myriad of colors, but sometimes they have trouble distinguishing between certain ones. The most common form of this condition is red-green color blindness, which happens to be the form that is most similar to a dog’s version of dichromatic color vision. Red-green color blindness causes the colors red, green, brown and orange to look similar to each other. While this definitely explains some of the outfit choices of my color blind friend from college (hey Jarrod!), it doesn’t give us the whole picture when it comes to dogs.
We have around 6 million cones in our eyes. The fovea, the center of our retina that focuses best, is made up entirely of cones. Dogs have far fewer overall cones and they do not have a fovea. Instead, the center of their retina consists of 20% cones. The rest consists of rods, which are better at detecting dim light. It’s one of the reasons your dog can see better at night than you can and why it’s easier for you to see faint stars in the night sky when you don’t look directly at them. This reduction in cones means the colors that dogs see are noticeably duller. To fully understand how that affects their color vision, think about the last time you were outside at dusk, just after the sun went below the horizon. The light outside is dim and colors are muted and harder to distinguish. You may not initially be able to tell the color of someone’s shirt until they walk closer to you. Bring your color blind friend along and ask them to describe what they see. That may be the closest you get to understanding how your dog views the colorful world around them. You can then tell your friend that comparing them to a dog is not an insult…except maybe to your dog.
So dogs do in fact see color! But they see fewer colors than we do, and the colors aren’t as distinct and vibrant. Still, that’s a far cry from living in a world of gray. Two of the colors dogs see the best are blue and yellow. You’ll notice these are the colors that we use for our Idle Paws Dog Training logo. That didn’t happen by random chance. Dogs are more likely to react negatively to things they can’t see as well, and we wanted to make sure they can clearly see our shirts – blue with yellow and white lettering – when we come for a visit. It all comes back to training in the end!
Neitz, J., Geist, T., & Jacobs, G.H. Color vision in the dog. Vis Neuro, 3, 119-125 (1989)
Michael Litzky is the Owner and Head Trainer of Idle Paws Dog Training. He is a Certified Professional Canine Behavior and Training Master Instructor and Behavior and Aggression Management Trainer. He is also a Certified Professional Dog Trainer-Knowledge Assessed. He has worked with thousands of dogs in all areas of dog behavior and obedience.