Why are dogs colorblind, and are dogs colorblind?

There are two types of cones on the dog's retina, which are able to recognize short wavelengths and medium-long wavelengths, that is, they can perceive blue light (light waves with short wavelengths) and red and yellow light (light waves with medium and long wavelengths). Due to the small number of cones, the colors of the world in the dog's eyes are very monotonous, not as colorful as the world in the eyes of humans. However, there are three types of cones in humans that allow us to see all the colors of light in the visible spectrum.

Because dogs have only two types of cones, dogs can distinguish the same colors as people with red-green color blindness. However, people with color blindness can see many other different colors, so can dogs see these colors as well? Scientists have taken two approaches to determining this.

One way is to shine a beam of colored light on the dog's eye, which results in an image that is reflected back from the dog's eye, and scientists study this reflected image; It is then compared to the same light reflected in the human eye. Another way is to train the dog to be able to"Tell"Scientists see the world as they see it. In the experiment, the scientists showed the dogs several sets of colors in a row, each group had three colors, two of which were the same.

With a very small amount of training, the dog will use its nose to point out to the scientists which color of light is different in each group. Scientists only need to repeat the process by changing the color of the light to come to the conclusion that the world is black in the eyes of dogs.

White and dark gray, mixed with medium and long light waves of red and yellow light and short light waves of blue light, the world is like a picture in a black and white TV, only the brightness of the black mortar is different, and the change of color cannot be distinguished. The reason why guide dogs can distinguish between red and green signal lights is that they rely on the brightness of the two lights. Dogs have a subtle ability to distinguish shades of gray, and with this ability, they can distinguish the changes in light and dark on objects, producing three-dimensional visual images.

Many sources and pet books believe that dogs are colorblind, but they have never been proven. According to the latest analysis by scientists, dogs are not color blind. Dogs have good eyesight, but they are a little different from humans.

Dogs' eyes also have color vision, but color is not very important to dogs.

In the human retina, there are rod-shaped and cone-shaped visual cells. The former is divided into light and darkness (black and white) of the environment, and the latter is divided into colors. Dogs have more rod-shaped cells than cones, so dogs can still see clearly in low-light environments.

From this, experts deduced that even the most colorful things appear in the eyes of dogs only in pastel hues.

Dogs are not colorblind, but color-weak, and are less sensitive to brightness and hue than humans; The main colors they can see are yellow, blue, and gray. The colors that dogs don't easily distinguish are red, green, and orange.

Labrador retriever.

Dogs' sense of smell is needless to say, compared to people, their olfactory system is much more developed, and their sense of hearing is also quite good. Because these two excellent abilities allow dogs to do a lot of work well, but their vision is not as good as the first two, and dogs seem to be born with color blindness. So why are dogs colorblind?

That's because dogs have fewer cones on their retina, so the world they see is not as colorful as we see.

The peculiarity of the dog's eye structure means that it can distinguish the same colors as a person with red-green color blindness. Scientists used to shine a beam of colored light on a dog's eye to get an image reflected back from the dog's eye, and scientists studied the reflected image and then compared it with the same light reflected in the human eye.

Some people may ask guide dogs are very accurate in judging traffic lights, why is that? In fact, guide dogs can distinguish traffic lights not because of the judgment of color, but by the brightness of the two lights. Studies have found that dogs have a subtle ability to distinguish shades of gray, and rely on this ability to distinguish light and dark changes on objects, resulting in three-dimensional visual images.

Although the dog cannot see red and green, it can be judged by the different grays in its eyes.

That's why dogs are color blind, but dogs' poor vision doesn't affect them, their sense of hearing and smell can make up for this deficiency, but the world in their eyes is not so colorful, it seems to be a pity.