Vision Of Cats

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Vision Of Cats
Vision Of Cats

Video: Vision Of Cats

Video: Vision Of Cats
Video: How Cats See The World 2024, March
Anonim

When they say about a person that he “sees like a cat”, this is a big stretch, since a cat's vision is very different from ours

Cats can see well under illumination 10 times lower than what we are able to see. At the same time, in good light, cats are worse at distinguishing details than we are. This is the first feature of feline vision. It is, as it were, specialized in the perception of a dimly lit space. That is why cats prefer shaded rooms, where they like to rest and make their toilet. And, naturally, those of them who like to hunt for mice are forced to do this in low light conditions, because their victims lead a twilight and nocturnal lifestyle. But cats, in addition to hunting, still have to make love at night, which we can guess, listening to the heartbreaking cries of March cats at night.

Face of a gray cat with green eyes, photo of a cat photo picture
Face of a gray cat with green eyes, photo of a cat photo picture

More recently, it was believed that cats do not have color vision at all and all the surrounding objects look black and white to them, much the same as we see them on the TV screen. However, it has now been established that cats are still able to distinguish, although worse than us, several colors. But what they distinguish much better than us is shades of gray, up to 25 shades.

This feature of vision can be explained by the color of their prey - mice and voles, whose fur color varies from light gray to dark gray and brownish gray. Primates, including humans, have never needed such a distinction between shades of gray, and therefore evolution did not give them this feature.

Watching a cat or kitten chasing a ball on a string, it is easy to establish that they react much more sharply to the horizontal movement of the toy. Thus, the ball that you roll on the floor always causes an active pursuit response in the cat, while the ball that you move up and down in front of it, it reacts more sluggishly. This is a reflection not only of her hunting instincts, since mice and voles move only in the horizontal plane, but also of her vision. It was found that the horizontal movement of objects is tracked by a cat in more detail and sharper than the displacement of the same objects in the vertical plane.

Since the main hunting technique used by a cat is waiting for the victim in ambush, and then an instant and accurate throw with open clawed paws, and not pursuing it, the cat's vision features well ensure the fulfillment of this task. Cats have a good view of the near space, and in the distance the contours of objects look slightly blurred for her. Both eyes of a cat are positioned close to each other and directed forward, forming an overlapping field of view. The resulting stereoscopic effect of binocular vision superimposes the images one on top of the other, creating a three-dimensional representation of the surrounding space. Stereoscopic vision allows the cat to more accurately assess the location of the victim in relation to its actions. At the same time, it is characteristic that in rodents, which are hunted by cats, the eyes are located on both sides of the head and see two independent pictures. At the same time, they do not have stereoscopic vision, but the space they view is doubled in comparison with a cat. Thanks to this orientation, it is easier for the rodent's eye to detect its main enemy - the cat.

Thus, we see that many features of feline vision are in one way or another related to the solution of the main life task - getting food. Of course, this was important even before their domestication, and now it is necessary for domestic cats living in rural areas. As for cats living in comfortable city apartments, they almost never have to catch mice. Nevertheless, their vision has retained all the mechanisms of adaptation, as well as behavior - hunting instincts. Therefore, when playing with your cat on a fluffy carpet, do not forget that this is a predatory animal with good eyesight and such sophisticated weapons as claws. But, of course, all "ecological "features of vision can be manifested in a cat only thanks to the perfect perceiving apparatus, consisting of eyes, optic nerves and cents in the cerebral cortex. The cat's eye is especially complex. The cat's eyes are large in comparison with the head, and slightly protruding. If a person had the same large eyes (in relation to body size), they would be about 20 cm in diameter. The eyeball lies quite deep in the socket, so the cat's eye movements are limited. To get a better view of an object in the periphery of vision, the cat has to turn its head. The eyeball is fixed and controlled by seven muscles.

Cat eyes, photo of a cat photo picture
Cat eyes, photo of a cat photo picture

Located in the outer part of the eyeball, the albuminous membrane in front forms the vitreous cornea, and in the rest of the opaque sclera. In the center of the iris (iris), the color of which is varied and gives special expressiveness to the cat's eyes, is the pupil. The pupil is elongated vertically and regulates the amount of light, changing its shape under the influence of light and with changes in emotional state, making the cat's eyes surprisingly attractive. Looking in them, we feel the magical power and involuntarily think about the cat's intelligence.

Behind the pupil is the lens, which acts as a lens and is attached by ligaments to the muscular ciliary body. In front of the pupil is the anterior ocular chamber, filled with aqueous humor, between the iris and the lens - the posterior ocular chamber. The cavity of the eyeball is filled with the vitreous humor.

In the choroid, consisting of a network of blood vessels feeding the eyes, at the exit of the optic nerve is a layer of cells with crystalline inclusions - a mirror. In the depths of the eyeball (retina) with visual cells - rods and cones. In a cat, as a crepuscular animal, the retina of the eye is mainly equipped with rods, and only in the central part of the retina, in the area of acute vision, are cones concentrated.

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The eyes are protected by the eyelids lined with mucous membranes. In the eye of a cat, unlike ours, there is a third eyelid, which moves the tear fluid through the eye and additionally protects the eye. Cats use their eyelids to regulate the amount of light entering the eye. There are more receptive cells in the cat's eye than in small primates, as well as more neurons in the visual centers of the brain.

All this helps the cat to catch moving victims in conditions of limited visibility, but when living in an apartment, these devices are redundant and almost never used in their full volume. They seem to exist with a cat just like that, just in case. What if you need it?

Source: Valery Ilyichev, Doctor of Biological Sciences, Professor, " Friend" magazine (cats) 1998 - 2

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