- Sep 17, 2019
The sight of a horse strongly differs from ours. And, as it in many respects defines behavior of these animals, we need to understand, how exactly horses see this world .
Structure of eyes of a horsethe Main objective which is carried out by sight of a horse — as soon as possible to notice
a predator. It is typical for the herbivores inhabiting open spaces.
At a horse the biggest eyes among all living beings. The size of eyes — 51х47.5 mm, and eyeball weight — about 50 grams. However on the mass of an eye concerning a body of a horse only on the fifth place: the cat, a dog, a sheep and a cow are ahead of them.
the Iris of the eye contains the pigmentary cages defining color of eyes of horses. As a rule, eyes at them — brown, various shades, but are also blue (in whole or in part). There are albinos — in an iris of the eye of their eyes there is no pigment, and the translucent blood vessels make an impression of red eyes. It is considered that albinos it is better than others see in the conditions of weak lighting.
of Eyes of a horse "is equipped" with a cross and oval pupil. It gives the chance to capture big space. In addition, photoreceptors on a retina are distributed unevenly. Shoots of nervous cages are concentrated in the concrete place and form a bunch — an optic nerve which delivers information in a brain. But there are no photoreceptors in this place, and light which is reflected from objects does not give the image. These are so-called "blind spots". Over a blind spot, it is a little sideways, the area of especially accurate sight — the central pole in which the set of flasks which are responsible for image sharpness is collected is located, on the contrary. Besides, flasks are collected along a horizontal thin line which passes through a retina. Thanks to the central pole, horses consider objects before themselves, and thanking tenches — located around.
of the Horse is much better, than people, notice the slightest movements on border of a field of vision even if look at closer subject.
are Seen by horses in the dark?
Near photoreceptors at horses is тапетум - it is a reflective cover. The light which passed through photoreceptors and is not absorbed tapetumy is reflected back and can be again apprehended by photoreceptors. Tapetum allows a horse to see even in the conditions of low illumination. Tapetum also forces eyes of a horse to glow in the dark if the ray of light gets on them.
the Horse sees
in the dark much better, than the person, approximately the same as an owl and a dog and worse, than a rabbit, a cat or a rat.
the Main difference of sight of horses from human
our eyes are located on a face, next to each other, and what is ahead, we see at the same time both eyes. But all the same the pictures perceived by the left and right eye differ. Besides the brain estimates distance to an object. Therefore at us the volume image turns out, we estimate a distance to a subject and between objects, the size of objects and we can present the approximate speed of their movement. This volume, or binocular sight. In the course of evolution when our far ancestors needed to calculate distance for a jump from a branch on a branch, it was extremely important.
of the Horse were anxious with another. They did not jump on branches, but escaped from predators on the open area, and review width was more important here. Therefore their eyes are located the heads on each side. And the most part of space seems it flat. This monocular sight.
. Our viewing angle — about 90 degrees. And the horse covers 350 degrees! One eye is capable to capture about 190 — 195 degrees, and a part of this space is blocked by area which the horse sees other eye. The horse sees this small site (from 30 to 70 degrees, depending on a shape of the head) volume.
did not hunt horses birds of prey therefore they did not learn to look into the sky. Though if desired, having lifted up the head, they can admire the Pole star, but the astronomy usually interests them a little.
about a blind zone. It is directly behind a tail and also directly before front hoofs. Certainly, she can turn slightly the head and see that she is behind, or, having hung the head, to study an object on the earth. In a blind zone of a horse do not see anything, and in boundary regions distinguish only the movement. Therefore it is not recommended to approach these creations behind, without having warned about itself — the horse can just be frightened of the fact that to her the predator crept and to decide to be protected. If it is necessary to approach behind, give to a horse the chance to hear you and to turn the head to be convinced that the back in safety.
Foals have other form of the head therefore their sight differs from sight of adult relatives a little. The binocular sight of foals is 20 degrees more down — that is they can almost see the hoofs — more widely in the parties.