Researchers once thought dogs were colorblind, but new evidence is showing our canine companions see the world very similarly to how we do.

For a long time, we believed our canine companions were colorblind, but new scientific research is shedding light on pets’ perception of color. Though Fido’s range of vision is limited compared to the range of colors humans see, our dogs do, in fact, see color.

Unlike people, who have three types of color-detecting cells—called cones—in their retinas, dogs only have two. This is why our pets’ range of color vision falls between the yellow and blue spectrum. But how can we be sure of what our pets see? Experiments by a University of Washington scientist found that dogs’ perception of color is comparable to that of people with red-green colorblindness, a common abnormality in humans. What most of us see as red probably appears to be dark brown to our dogs, while green, yellow and orange probably to take a yellow hue.

A study by researchers at the University of Bari backs these findings. In the experiment, the team used a variation of the Ishihara Test for Color Deficiency, which is used to test for colorblindness in humans. The test involves a series of colored circles depicting numbers, which are imperceptible to those with red-green colorblindness. To adapt this test for canine participants, the researchers designed plates showing a series of silhouettes of running cats. Based on results, they concluded that dogs could easily spot a bright red cat on a green background, but their perception of the silhouette dropped off when the cat was comprised of speckled light- and dark-red circles.
 
Dogs may be less able to distinguish color than humans,  but this does not mean their vision is inferior. Compared to ours, canines’ eyes contain more light-sensitive photoreceptors, allowing them to see well in dim light. From an evolutionary standpoint, this provided benefits such as allowing our pets’ ancestors to see better during dawn and dusk, when they were most likely to hunt and color vision was less crucial. Much like people with colorblindness, dogs developed other heightened senses to make up for their limited range of vision. Take, for example, Fido’s impeccable sense of smell, which is roughly 40 times great than our own.
 
While their vision capabilities are slightly different than ours, dogs see the world in a way that is comparable to what we see. Combined with Fido’s keen nose and other senses, our pets are more than adept at navigating their daily lives—even if their world does look slightly different than our own.