As you can see dogs: especially their vision
Since ancient times, dogs are our friends and live in families. No wonder people are so interested in the details of the structure of their body and how it functions, what is the psychology of a four-legged pet. Studying all this long ago by scientists, veterinarians, zoopsychologists. For example, one question which is: “As you see the dog?” Although scientists have already received an answer, not all owners and breeders known. Explanations often contain incorrect information, one of the owners walks a lot of myths about how eyesight in dogs.
Like humans, Pets visual function provides a special organ — the eye. He doubles, all animals have two of them. In principle the structure of the organs of vision is the same for people and dogs. However, there are some differences.
As you can see dog day?
Daylight vision, they have generally not better than a human. But for the predator is not of great importance. The structure of their eyes like the entire body, the most adapted for other purposes, due to their way of life.
Features vision dogs colors — one of the main issues that interested the people. Not so long ago it was established that dogs can distinguish colours and vision is not black and white as previously thought. However, it is still not the same as ours. It is known that in the eye has special cells called receptors, which have different shapes, the so-called “cones” and “rods”. The first is responsible for the color perception, the second one for the sharpness and night vision. Cones are of three types: perceiving a red-orange color range, yellow-green and blue-violet. Dogs have fewer of these cells in General, completely absent the first kind. In this regard, the difference between the red and yellow-green these animals do not perceive.
However, they are able to better distinguish shades of gray. This is due to the presence of a larger number of sticks and their sensitivities. This particular dog is required and an exceptional ability to see a moving object at a far distance. Due to the location of these receptors close to the optical axis of the eye, where people is the “yellow spot” with cones, the distance of the pet determines a lot better than people. Near the animal doesn't see very well: all objects at a distance less than 30 cm is spread out.
By the way, the field of view in dogs, elongated, oval (people round) and the axis of the eye is directed not parallel to each other and diverge at an angle of about 20 degrees. This significantly expands pet review. Of course, breeds with a short muzzle, the figure is closer to that of humans.
Animal it refers to a transition between day and night, therefore, must have perfect sight in any light. As already mentioned, a large number of sticks determines the benefits of daylight vision, but it also has value and lack of light. There is another point: dogs in the layer of rods and cones is present in another layer, called the tapetum (Tapetum), which consists of a reflective pigment. Due to the fact that almost all falling into the eyes of light perceived by cells, night vision dogs 3-4 times better than a human.
Of course, what you know now about how dogs see, can scarcely influence your choice of pet for families. Breed differences in color and svetofore no. Genetic predisposition a particular breed exists only to different kinds of diseases of the organs of vision.
Choosing is adequate for your family pet, of course, rely on these data as well as information about other tendencies to disease. But first of all you have to do the choosing a dog for the home respectively for the purpose for which it withdrawn, its exterior features and its capabilities, including financial.