Is My Dog Really Colorblind?

It used to be generally believed that dogs are colorblind, and for a while this was a widely accepted fact. However, the information was misinterpreted and misunderstood. The truth is that dogs do not see the world only in black, white and gray, they do indeed see color. However, they don't have the ability to see the range of color that humans do.

The light-receptor cells in the retina at the back of a dog's eyes are different in structure, to those of a human. The retina in humans and dogs performs the function of a movie screen. Light is focused and then translated into shapes and colors, which are then, in turn, translated by the brain, into the images that we perceive.

Dogs have a similar set up in light-sensors to those of humans. These are known as cones and rods. The misunderstanding regarding dogs seeing the world in shades of black, white and gray, stems from the fact that dogs have many more rods than we do, and rods are the sensors that respond to shades of black and white. These rods, in dogs, are situated right in the middle of the eye.

Cones, on the other hand, are mainly responsible for visual sharpness and clarity. They detect color, and determine how well we are able to see. Humans have three different types of cones, and they respond best to green, blue and red. This enables people to detect a wide spectrum of hues.

The difference in the eyes of dogs is they are missing the red-responsive cone. So the truth is they are partially color blind, but they are able to see blues, greens, yellowish hues, and shades of brown and gray. The experiments conducted in order to ascertain this information were carried out using different colored toys. Dogs were taught to pick out toys that were a different color to the others. Researchers discovered that the toys that were of the color that the dogs were unable to identify was unrecognizable to them.

The colors that are recognizable by dogs do make sense, when you consider their ancestry. Red and, yellow and orange are not colors that would have been of any importance for primal canines. They will only have needed the blues and greens, along with the shades of black and gray, and of course, white. It is only now, in modern times that dogs have come across the range of colors and hues we have access to, in the brightly colored and varied toys and accessories.

It's interesting to note, if you throw a green ball into grass, it's very possible your dog won't be able to find it, unless, of course it has a strong scent and he uses his nose. Our dogs do rely more on their noses anyway, so that sense is much stronger than their ability to see color.

In a way their color blindness is similar to that of some humans. They do see colors, but are not able to identify them.

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