Dog Color Blindness

Dog owners often raise questions about whether dogs are colorblind or whether they can only see shades of gray. Well, it may be surprising for many to learn that a dog is actually colorblind. In other words, dogs do not have the ability to see colors. However, this inability to see colors is compensated for, by their keen sense of smell and hearing. While dogs may not have the color range and visual acuity (focus) that we depend on, their night vision is far superior to normal humans. This is because of the reflective structure behind their retina called the tapetum lucidum that dogs can see objects in the dark.

It should be noted that dog colorblindness does not mean that they cannot see any colors; it simply means that they cannot see the same color range that we can. Owing to low visual acuity, dogs cannot focus as well. Thus, an object that a human can see clearly, will appear blurred to a dog from the same distance. A rough estimate is that dogs have about 20/75 vision, which means that they can see objects clearly at 20 feet while a normal human can see clearly at 75 feet.

How Dogs See Color

The central position of a dog’s retina is composed primarily of rods, which need less light to function. So dogs can see in dimmer light as compared to humans. The central retinas of humans have primarily cone cells, the ones responsible for perceiving color. Dogs have a dichromatic color vision as they have two different color receptors in their eyes, whereas humans have trichomatic vision. One of the color receptor peaks at the blue-violet range and the other at the yellow-green range. This means that dogs lack the ability to see the range of colors from green to red which is called deuteranopia (red-green color blindness).
Dogs do have advantages over the normal human vision as they respond to an image rapidly and detect the slightest motion. Dogs have a better peripheral vision. Also, dogs can see flickering light better than humans.

Hence, although dogs are colorblind, they can see colors, albeit the colors that they see are neither as rich nor as many as those seen by humans. Humans see the rainbow as violet, blue, blue-green, green, yellow, orange, and red; whereas dogs would see it as dark blue, light blue, gray, light yellow, darker yellow, and very dark gray.