I spent years training to be a scientist, so I pride myself on my powers of observation. But you don’t have to be a scientist (or particularly observant for that matter) to see that my dog loves cheese. She could be sound asleep on another floor of the house, but as soon as I start to open a cheese wrapper she is immediately by my side. Even when she sees me coming with the dreaded ear medicine, as long as I’m holding cheese she is at my beck and call. Whenever I’m in the kitchen, she’s under my feet waiting for me to drop something—especially if it’s cheese. The perplexing thing is, whenever I drop shredded cheddar cheese on the floor she never reacts. If I draw her attention to it, she’ll eat it but it’s almost as if she doesn’t see the cheddar cheese. This happened enough times that I designed an experiment. Wondering if it had something to do with the way she sees color, I dropped some shredded carrot on the floor. Once again—no reaction. At that point, I became convinced that my dog can’t see the color orange. This got me wondering: can dogs see colors the same way we do?
The short answer is no. To understand why, let’s review how our eyes see color.
How Our Eyes See Color
We see color based on how the cells within our eyes react to different wavelengths of light. The retina, located at the back of the eye, contains millions of photoreceptors (cells that detect light). There are two types of these photoreceptor cells: rods and cones. Both rod and cone cells are connected to the optic nerve, so signals received by the photoreceptors are converted to messages that are sent to the brain.
Humans rely on rod cells for peripheral vision and for detecting light levels. Rod cells are sensitive to low levels of light and are what enable us to see in the dark. Cone cells are the photoreceptors responsible for seeing color. Through the action of our cone cells, humans are able to perceive all of the colors of the visible spectrum.
What Colors Dogs Can See
Like human eyes, dog eyes contain both rod and cone photoreceptors. However, while humans have three types of cone cells—each able to detect different color ranges (red, green, and blue)—dogs only have two types of cone cells (green and blue). Consequently, dogs are unable to discern colors that fall in the red-orange range of the visible spectrum. While they can clearly see the colors yellow and blue (and their combinations), dogs see most of the world as a grayish-brown.
Websites and apps are available which allow you to see the world the way a dog does. On the website Dog Vision, you can upload a picture and the website tool will convert the image into one representing the way a dog would see it. Phone and device apps, including Dog Optics and Dog Vision HD, also allow you to “see like a dog”.
What About Other Animals?
Given the variety of animals on the planet, it comes as no surprise that animal species differ in their ability to see color. Like dogs, many mammals have only two types of cone cells. Examples of these animals with so-called dichromatic vision include squirrels, rabbits, cats, and deer. (This is the reason hunters wear hunter orange while deer hunting. While other hunters can easily see the blazing orange, deer can’t discern the color). Other animals can see colors that humans can’t see. Many insects can see colors in the ultraviolet range while snakes can discern colors in the infrared spectrum.
Check out this video to learn more:
While my dog may not be able to see her beloved cheddar cheese, there’s nothing wrong with her sense of hearing. She will continue to come running when she hears the sound of cheese wrapper, so there’s little chance of her going hungry no matter what colors she can or can not see.
This video summarizes how our eyes work with our brain to see the colors of the visible spectrum: