10 interesting facts about eyes and sight

Eyes – unique body on the structure thanks to which the person obtains about 80% of information on the world around: about a form, color, size, the movement, and also many other parameters of objects or phenomena. But whether much we know about the most valuable sense body which, according to the scientist Sechenov, provides us about one thousand various feelings a minute? Let's consider 10 most surprising facts about eyes and sight.

Fact 1. Average diameter of an eye - 2,5 cm, weight - about 8 grams, and these parameters in shares of percent are similar to distinction at all people who reached seven years. Diameter of an eye of the newborn child - 18 mm, weight - 3 grams. Only 1/6 part of an organ of sight are visible to the person whereas his internal part is connected with an organism the optic nerve transporting information in a brain.

Fact 2. A human eye is capable to perceive only 3 sites of a range - green, blue and red. Other distinguishable shades (their more than hundred thousand) are derivative of these three flowers. Only 2% of women have the additional site of a retina allowing to distinguish up to 100 million shades. All children are born far-sighted color-blind persons, being not capable to perceive colors, however at 8% of males daltonism remains at adult age.

Fact 3. All people - blue-eyed. Distinction of shades of an iris depends on amount of the melanin concentrated in it. The highest it at owners of brown eyes and the lowest - at light-eyed. So, all children are born with gray-blue eyes which later gain 1,5-2 the genetic color. Thanks to this fact the laser procedure of correction of color clearing an iris of melanin was widely adopted. It allows to change in 1 minute brown color of eyes to blue; at the same time it is impossible to return back former shade.

Fact 4. About 1% of people on the planet have different colors of eyes - the genetic deviation which is called a heterochromia. The phenomenon can serve as a consequence of injuries, diseases, genetic mutations and is explained by excess of melanin in one organ of sight and its lack of another. At a partial (sector) heterochromia of people has sites of different color on one iris, at absolute - two different colors on both eyes. More often than at people, a heterochromia occurs at animals: cats, dogs, horses and buffalo s. In the ancient time the people suffering from a heterochromia were considered sorcerers and witches.

Fact 5. One of the most rare shades of human eyes - green. This beautiful color of an iris turns out thanks to existence in its enveloping layer of a yellow pigment of the lipofuscin connected to blue or blue shades in a stroma. It occurs only at 1,6% of the population of the globe and is eradicated in families by the dominating gene of brown-eyed.

Fact 6. The cornea of eyes of the person is similar in the structure and a structure of collagen with spark which is often used as substitute at operations in the eyes. Today the keratoplasty of the sea predator to the person (zooophthalmology) is a highly effective method of treatment of a serious illness of body and recovery of sight.

Fact 7. The retina of an eye of each person is unique and has 256 unique characteristics (the probability of repetition at two different people makes 0, 002%). Therefore scanning of an iris of an eye on an equal basis with dactyloscopy can be used for identification of the personality. Already today the procedure of recognition for an iris of the eye of the person is used in customs services of the USA and Great Britain.

Fact 8. An oculomotor muscle - the most bystry in an organism. Process of blinking lasts about 100 milliseconds or 5 times in one second. Every second the crystalline lens of an organ of sight can be focused on 50 objects, and only falteringly; eye muscles can make the smooth movements only watching a moving object.

Fact 9. We see not eyes, but a brain. The organ of sight only provides to a brain information (and in the turned look) which its relevant departments decipher in the form of pictures and images. Thus, at failure of work of a brain even at normal functioning of eyes of the image can be perceived in the distorted look. One standard test for the movement of eyes is capable to reveal with an accuracy of 98% at the person existence of schizophrenia - the serious mental illness connected with failure of its thought processes.

Fact 10. The most unusual color of eyes - red. Due to absence in a melanin eye retina the iris looks red because of the blood vessels which are translucent through it. From mixing of red color of eyes and a blue shade of a stroma violet color can turn out (versions - lilac, ultramarine, amethyst). The similar deviation meets at albinos more often and has exclusively rare character.