Recall the hackneyed phrase: "A dog is a friend of man!" Yes, this statement is difficult to argue. After all, four-legged pets are the most loyal, reliable and affectionate. And they are extremely intelligent and capable. Do you think dogs distinguish colors?
Until recently, it was believed that they see the world only in black and white and no longer distinguish any shades of the spectrum. But then it turns out that they perceive the rainbow after the rain, for example, in the form of white and black stripes, but they don’t see other colors at all, well, or they look blurry. The fallacy of such a theory has been refuted by modern scientists. It was proved that, unlike human ones, the dog’s eyes are not able to see the whole spectrum, however, several basic colors are still available for their perception.
The world through the eyes of a ball
As you know, the eye distinguishes colors using nerve cells. There are two main rods in the retina that determine the level of illumination and dynamics, as well as cones responsible for color recognition. Human eyes contain three types of such cones. They are able to distinguish combinations of blue, red and green. Dogs have only two such cones. Therefore, they have two-tone vision. And the question of whether dogs distinguish colors can be answered with confidence: only yellow and blue can perceive their eyes.
But our four-legged friends can see in the dark and clearly determine the movement of objects. Rod cells give this ability. And dogs have much more than humans.
Color blindness: what is it
To understand whether dogs distinguish colors, it is worth mentioning a phenomenon such as color blindness. This is a special term for determining the ability to distinguish colors. Its level is determined by the number of receptors capable of perceiving the color gamut. There are two main types of human color blindness: red-green and blue-yellow. Color blind are not able to distinguish the specified colors. So, if you put two vases in front of him - one red and the other green, he will not be able to see the difference between them. They both seem gray to him. And what colors do dogs see? It turns out that their color perception is similar to red-green color blindness in humans.
What is the difference?
If the ability of animals to perceive the colors of the spectrum is limited by the number of shades, this does not mean that dogs cannot distinguish colors. They simply cannot see the color as is customary in humans. So, red objects they seem dark gray or even black. Green and orange will be pale yellow for them. Blue is a little easier: the dog’s eyes see it almost the same as we perceive it. But all its shades for them are simply indistinguishable. For example, purple will be perceived as blue too.
Scientists conducted an interesting experiment with several breeds. To determine whether dogs distinguish colors, subjects were offered balls of two colors: red and yellow. They were given in turn. At first they were offering red ones, and a bit later some of them were imperceptibly replaced with yellow ones. None of the dogs saw a color difference. But thanks to the excellent sense of smell, they were still able to determine which of the balls appeared later. That is, the main factor here was not vision, but scent.
By the way, color perception is not the only difference between a dog’s eye and a human one. Dogs see well at dusk. But not in all situations their eyesight is so sharp. Sometimes dogs can be called myopic. For example, if a person and a dog are nearby and are looking at the same object located at a certain distance, then the image may appear blurry to the animal, and to the person more clearly. For example, a dog cannot see an object under its nose, but it finds it by smell. Animals also do not respond to changes in color brightness - their eyes are not as sensitive as ours. Unfortunately, the world around them is not as bright for them as it is for us.
Dog Vision Features
But it is not all that bad. In some ways, the dog’s eyes are superior to ours. Yes, not all colors are perceived by them, and their vision is not so sharp, but these disadvantages are compensated by the fact that their eyes are located on the sides of the head. This makes the angle of peripheral vision much wider, thereby balancing the lack of visual acuity.
Rod cells located in the dog’s eyes make it possible to absorb the maximum amount of light. And the reflective cells under the retina make them shiny and allow you to see perfectly at dusk and at dawn. Their eyes seem to glow in the dark. But they simply reflect the light falling on them, like spotlights. And one more advantage: the canine eye has a larger number of cells in the retina, which are responsible for identifying the movement of objects in space even at large distances. That is why they often bark with their heads up. It seems to us, often for no reason. They are attracted to birds flying at high altitudes, and we may simply not see them.
Why does a dog need such sight?
Nature made sure that dogs could not only feed themselves and their offspring, but also not become prey for predators. The ability to see at dusk, to distinguish the slightest movement at a great distance initially helped to survive in the wild. Nowadays, many of them have warm housing and enough food that does not need to be obtained - just go to the bowl. But the unique visual possibilities remain the same. This should be considered by dog ​​owners.
Even choosing a toy, you can be sure that, for example, a pet will like a yellow or blue ball more than red or green. So now, understanding the principle of this perception, it is much easier to guess the needs of animals and make the pet’s life more enjoyable.