Goat pupils: why such a form?
Almost all people have ever seen a goat in their life. But hardly anyone had the desire to look into her eyes. And if you looked, you would have experienced some surprise when you saw the shape of the pupils. Read on, and you will find out which pupils are in the goat and what is remarkable about them.
Most often people believe that the pupils of allanimals are round. This opinion is formed by analogy with the human eye. But this is not true, in many animals the pupil has a completely different shape, for example, the goat pupils are arranged horizontally.
In the daytime they look like a narrow slit. When the pupils expand, the goats turn into rectangles.
Why you need a rectangular pupil
Due to this shape of the pupil, the viewing angle of the goatIt reaches 340 degrees without taking into account the rotation of the head. That is, when grazing the goat has the opportunity to observe what is happening, without lifting or turning the head. For comparison: the review of vision in humans - only 160-180 degrees with immobility of the head.
In the daytime, under strong light, pupilsgoats are strongly narrowed and look like slits. The narrowing of the pupil serves for the most part to protect the eyes of the goat from sunlight. With the advent of twilight and night time, the pupils expand, taking the form of rectangles. In a strongly darkened room or with a strong excitement in a goat, the square pupils are achieved by further expanding the pupil. This mechanism contributes to all the same - a better overview in the dark. Goat, like other animals that have the same pupils, is able at night to notice a moving predator almost behind itself. This helps the animals to have time to notify other animals in the herd and hide, avoiding death.
Goat pupils give the animal an opportunityfeel relatively safe, because, having almost circular vision and a propensity for herd residence, a group of goats can safely graze. When a predator appears in the field of view of at least one of the goats, the entire herd will have time to escape.
Interestingly, having such wonderfulthe ability to see around him and in the dark, goats are unable to assess the distance to various objects. These animals can not even correctly determine the direction of motion, since their spatial vision is very poorly developed.
The appearance of the shape of pupils of goats
Such a pupil was formed in the goat and otherartiodactyls millions of years ago. Initially, most likely, the pupils were round, but with constant exposure to the sun the pupil began to taper. As the animals eat, lowering their heads low, the pupil begins to narrow in the horizontal direction, in order to enable them to survey the horizon without detaching themselves from the food. Gradually, the muscles formed inside the eye, which close the goat pupils to the crack in bright light. In the dark, these muscles relax, so that animals can eat at night with the same quality of vision.
Who else has a rectangular pupil?
Of domestic animals, pupils of the same shape havesheep. In the wild, almost all artiodactyls have this feature. In addition to the cloven-hoofed rectangular pupil, oddly enough, there are also octopuses and mongooses: they also need to protect the pupil from bright sunlight for nightlife. And to control the horizon for these living organisms is also a vital task.
Various types of pupils reflect a differenta way of life, different habits and needs. To understand why and from which the pupils have a different shape, you just need to analyze what we know about living things. And then both the horizontal rectangles of the goat, and the vertical slits of cats, and the predatory squint of the shark will become clear. You just need to look into someone's eyes except yourself.