Dogs have been our friends since ancient times and live in families. It is not surprising that people are so interested in the details of how their body works and how it functions, what is the psychology of a four-legged pet. Scientists, veterinarians, zoopsychologists have been studying all this for a long time.
Here, for example, is one of the questions that occupies people: “How do dogs see?” Although scientists have already received an answer to it, it is not known to all owners and breeders. Explanations often contain incorrect information, there are many myths among the owners about what kind of eyesight dogs have.
As in humans, in pets, the visual function is provided by a special organ - the eye. It is paired, all animals have two of them. The fundamental structure of the organs of vision is the same in humans and dogs. However, there are also differences.
How do dogs see during the day?
Their daytime vision is generally no better than a human's. But for a predatordoesn't play a big role. The structure of their eyes, as well as the whole organism, is maximally adapted for other purposes, due to their lifestyle.
Features of color vision by dogs is one of the main issues that worried people. Not so long ago it was established that dogs distinguish colors, and their vision is not at all black and white, as previously thought. However, it is still not the same as ours. It is known that in the eye there are special receptor cells that have different shapes, the so-called “cones” and “rods”. The former are responsible for the perception of color, the latter for sharpness and night vision. There are three types of cones: red-orange, yellow-green, and blue-violet. Dogs have fewer of these cells overall, and the first variety is completely absent. In this regard, these animals do not perceive the difference between red and yellow-green.
However, they are able to distinguish shades of gray well. This is due to the presence of a larger number of sticks and their increased sensitivity. The dog also owes this feature to its exceptional ability to perfectly see a moving object at a long distance. Due to the location of these receptors close to the optical axis of the eye, where people have a “yellow spot” with a cluster of cones, a pet determines the distance much better than a person. Up close, the animal does not see very well: all objects at a distance of less than 30 cm are already blurry.
By the way, the visual fields in dogs are elongated, oval (inpeople are round), and the axes of the eyes are not directed parallel to each other, but diverge at an angle of about 20 degrees. This greatly expands the pet's field of view. Of course, in breeds with a short muzzle, this figure approaches that of a person.
How do dogs see in the dark?
This animal refers to the transitional between day and night, therefore, it must have excellent vision in any light. As already mentioned, a large number of rods determines the advantages of daytime vision, but it also matters when there is a lack of light. There is another point: in dogs, behind the layer of rods and cones, there is another layer called tapetum (Tapetum), which consists of a light-reflecting pigment. Due to the fact that almost all the light falling into the eyes is perceived by cells, dogs' night vision is 3-4 times better than human.
Of course, what you now know about how dogs see is unlikely to influence your choice of a family pet. There are no breed differences in color and light perception. The genetic predisposition of a particular breed exists only to various diseases of the organs of vision.
When choosing an adequate pet for your family, of course, you should focus on these data as well as on information about other disease susceptibility. But first of all, you must choose a dog for the home according to the purpose for which it was bred, its exterior features and your capabilities, including financial ones.