How dogs see: the features of their vision
Dogs from ancient times are our friends and live in families. It's no surprise that people are so interested in the details of how their body works and how it functions, what is the psychology of the four-legged pet. Scientists, veterinarians, zoopsychologists have been studying this for a long time.For example, one of the questions that people occupy: "How do dogs see?" Although scientists have already received an answer to it, not all owners and breeders are known. The explanations often contain incorrect information, many myths are walking among the owners about the sight of dogs.
As in humans, in the home pets, the visual function is provided by a special organ - the eye. He is a pair, all animals have two. The basic structure of the organs of vision is the same in humans and dogs. Nevertheless, there are differences.
How do dogs see the day?
Daytime vision in them as a whole is not better than human. But for a predator it does not play a big role. The structure of their eyes, as well as of the whole organism, is maximally adapted for other purposes, conditioned by their way of life.
The features of seeing dogs in color are one of the main issues that worried people. Not so long ago it was found that dogs distinguish colors, and their vision is not black and white at all, as was previously thought. However, it is not the same as ours. It is known that there are special receptor cells in the eye, which have different shapes, so-called "cones" and "sticks." The former are responsible for the perception of color, the latter for acuity and night vision. The cones are of three types: perceiving the red-orange range of colors, yellow-green and blue-violet. Dogs have fewer of these cells as a whole, the first variety is completely absent. In this regard, the difference between red and yellow-green, these animals do not perceive.
However, they are able to clearly distinguish shades of gray. This is due to the presence of a greater number of rods and their increased sensitivity. This feature is also due to the dog's exceptional ability to see a moving object at a great distance. Due to the arrangement of these receptors close to the optical axis of the eye, where a "yellow spot" with a cone cluster is located in people, the distance of the pet determines much better than the person. Near the animal does not see very well: all objects at a distance of less than 30 cm are already blurred.
By the way, the field of view in dogs is elongated, oval (in people - round), and the axes of the eyes are not parallel to each other, but diverge at an angle of about 20 degrees. This greatly expands the pet's review. Of course, in rocks with a short muzzle, this indicator approaches that of a person.
Animal this refers to the transitional between day and night, hence, should have excellent eyesight in any illumination. As already mentioned, a large number of rods determines the benefits of daylight, but it also has value in the case of a lack of light. There is one more point: in dogs behind a layer of rods and cones there is another layer, called tapetum (Tapetum), which consists of a retro-reflective pigment. Due to the fact that almost all the light falling into the eyes is perceived by the cells, the night vision of dogs is 3-4 times better than the human.
Of course, what you now know about how dogs are seen can hardly affect your choice of pet for the family. There are no natural differences in color and light perception. The genetic predisposition of this or that breed exists only for various diseases of the organs of sight.
Selecting an adequate for your family pet, of course, should rely on these data as well as on information on other inclinations to diseases. But first of all you should make a choice of a dog for the house according to the purpose for which it was taken, its exterior features and its capabilities, including financial ones.