Interesting facts about human vision. Curious facts about vision Amazing properties of the human eye

Every day a person blinks 11,500 times!

Eye

The weight of the eye is 7-8 g, the diameter of the eyeball is 2.5 cm. The human eye is 15 times smaller than the eye of a giant squid with a diameter of 38 cm, the size corresponding to two human heads.

Eyelashes

Eyelashes protect the eyes from dust and ensure that the eyelids close when touched by a foreign object. Since there are 80 eyelashes on each psx, our eyes are protected by a real curtain of 320 eyelashes. Eyelashes fall out and grow back in 100 days. Thus, a man will change his eyelashes 260 times in his life, and a woman – 290. The total number of eyelashes for men and women is 83,000 and 93,000, respectively.

People suffering from poor vision have a fixed gaze and rarely blink. Men usually blink once every 5 seconds. Minus 8 hours of sleep, they blink 11,500 times daily. Over the course of a lifetime, a man blinks 298 million times, and a woman blinks 331 million times.

Tears

Lacrimal fluid (tears) moisturizes the surface of the eye. In the absence of tears, dehydration of such a delicate organ as the eye would occur, and blindness would occur very quickly. The lacrimal glands of both eyes produce three thimbles of tears (0.01 L) daily.

Tears rid the body of chemicals associated with nervous tension, the content of which is reduced by 40%. Not as a reproach to women, it should be noted that due to the secretion of a hormone with the pleasant name “prolactin”, they cry four times more often than men.

Vision

The mechanisms of operation of the eye and the camera are similar. Depending on the aperture, more or less light enters the camera. The role of the diaphragm in the eye is performed by the pupil (the dark spot in the center of the iris). Rays of light reflected by an object pass through the camera lens, and in the eye - through a kind of lens-lens located inside the eyeball. In the camera, these rays of light then converge on the photographic film and capture the inverted image on it. This completes the photography process. In the eye, light rays are captured by the retina (at the back of the eye), which is equipped with 132 million receptor cells - “image receptors”, including 125 million rods that provide light perception and 7 million cones that provide color perception. (The layers of the retina are called “rods” and “cones” because of their shape.) As the image is transmitted to the brain, the image is transferred to the optic nerve.

The eye itself can focus (accommodate) to see near and distant objects. A person with normal vision is able to clearly see objects at a distance of 60 m. The eye can distinguish objects at a distance of less than 5 m. The minimum limit for clear vision in a young person is 15 cm, but at a closer distance objects become blurry. However, this limit changes with age: 7 cm at 10 years old, 15 cm at 20 years old, 25 cm at 40 years old, 40 cm at 50 years old. The increase in the limit with age is explained by farsightedness. In conditions favorable to vision, with good lighting, the eyes can accurately distinguish 10 million shades.

The three-dimensionality of the image arises because we see with two eyes.

A person's full viewing angle is 125 degrees. For comparison, we note that in cats this figure is 187 degrees.

Human visual acuity is 500 times lower than that of owls, which are able to distinguish their prey from a distance of 2 m in almost complete darkness. Here are other striking examples: a golden eagle can spot a hare from a height of 3.2 km, and a falcon can spot a pigeon more than 8 km away.

The iris of the eye is a colored diaphragm that can change color in the first years of a person’s life. Both fingerprints and iris patterns are unique to each person.

Blind spot

One area of the retina, the so-called blind spot, does not have photoreceptors and therefore does not perceive light. This is where the optic nerve exits the retina. The blind spot, however, does not prevent us from seeing - the brain for the most part “ignores” it.

Vision defects

Myopia is the inability to see distant objects clearly. In this case, the muscles do not relax the lens enough, so the light rays are focused in front of the retina and the image on it turns out blurry. This deficiency can be corrected by using contact lenses or glasses with concave glass lenses that scatter the light beam.

Farsightedness is the inability to see close objects clearly. In farsighted people, the muscles do not compress the lens tightly enough, so light rays are focused behind the retina and the image also blurs. Glasses with convex lenses that concentrate light help against farsightedness.

Color blindness, or color blindness, is the inability to distinguish certain colors.

The boy Vovka quickly, deftly wanted to untie the rope. To untie the knot, he began to pry it with an awl. The awl bounced off with force - Volodya’s eye was damaged... You can only handle the awl very carefully. Don’t keep awls, scissors, knives as toys, because it’s very easy to hurt your eyes with a sharp object! Natalia Orlova

The nervous system constantly receives signals from the outside world using special sensors. They are called sense organs. Eyes Light is perceived by the organs of vision - the eyes. From them to the brain the path is very short. The eyes are his outgrowths! Your eyes are like two cameras or two television cameras that are aimed at the world around you. The outer opening of the camera is usually covered...

One summer, a boy named Petya Vorobyov was scaring them in the garden and, forgetting about everything in the world, shot at them with a slingshot. Once! Another! And for the third time! Suddenly he hit his brother in the eye - Almost knocked out his brother’s eye!.. Don’t shoot with slingshots! Natalia Orlova

Tongue The tongue is a muscular organ located in the oral cavity. Its length is 9 cm, width 5 cm and weight 50 g. The tongue is formed by muscles connected to the base of the lower jaw and allowing it to perform many movements, for example, folding, rotating (up to 40 times per minute kiss), etc. The functions of language are varied. Due to its mobility (on average up to 80...

There was once a case like this: There was a cartridge lying on the ground, the guys hit it with a stone - and it exploded loudly! The car with Andrey is rushing to the hospital - Get treatment quickly! Hurry!.. Hurry! And in the hospital there is silence. The boy’s bed is long... The boy is crying, very pale - A copper shard got into his eye!.. And early the next morning the Doctor said to the sisters: “Bring the boy to the operating room!” This room is clean, simple, There is a strong smell of medicine, It’s creepy here...

The sense of taste and smell are closely interconnected. A wide variety of taste sensations are created by the combination of taste and smell. Receptor and supporting cells are located in the taste bud, like orange slices. The taste bud recognizes substances dissolved in saliva, which enter the bulb through the taste duct, which opens on the surface of the tongue. The organ of taste is the tongue. On its upper side there are more than 10...

With poor eyesight, guys, living without glasses is torture! You walk along your dear street timidly, like a stranger. Don't you understand - a poster? Poster? Who's coming - Ilyusha? Grisha? It’s hard to recognize people you meet, It’s bad even to play ball... The doctor prescribed glasses for Maya And at the same time he told her: “You wear them without taking them off, So that your eyes don’t get damaged.” Maya began to say: “I won’t wear them, Children at school will often call me...

There are 200 million olfactory cells in the upper posterior part of the nasal cavity! Pleasant and pungent odors floating in the air are captured by the nose and then transferred to the odor receptor (olfactory mucosa), with a surface area barely equal to the size of a postage stamp (3 cm2). 200 million cells (olfactory receptors), equipped with odor detectors and having nerve endings in the form of hairs, capture the smell...

Suddenly little Slava’s eyes began to squint, the right one began to shift towards his nose, What should I do here? How can we be here? Doctor Slava examined him and ordered him to wear glasses: “Such a squint so that it doesn’t disgrace you, Here is our conclusion: Glasses are one cure.” They boldly go to the pharmacy, Mom bought glasses, put them on for Glory, and her eyes stood up straight. Natalia Orlova

Let's figure it out together, children: What are eyes for in the world? Why do we all have a pair of eyes on our faces? Varya’s eyes are brown, Vasya and Vera’s are gray, little Alenka’s eyes are green. What are eyes for? So that tears flow from them? Close your eyes with your palm, Sit just a little - It immediately became dark: Where...

Interesting facts about human eyes. Few would argue that our lives would be unspeakably boring without our five senses. All of our senses are important to us, but if you asked a person which of them he is least willing to part with, then most likely you would choose vision. Below are some strange and Interesting Facts that you may not have known about your eyes.

1. We blink up to 10 million times a year.

2. All children are colorblind when they are first born.

3. A baby's eyes do not produce tears until he is 6 to 8 weeks old.

4. Cosmetics cause the most damage to the eyes.

5. Some people start sneezing when bright light enters their eyes.

6. Scientists believe that the golden color helps restore vision!

7. The space between the eyes is called the glabella.

8. The study of the iris of the eyes is called iridology.

9. The cornea of a shark's eye is often used in surgical operations on the human eye, as it has a similar structure.

10. The human eyeball weighs 28 grams.

11. The human eye can distinguish up to 500 shades of gray.

12. It’s a paradox, but when reading quickly, eye fatigue is less than when reading slowly, and this is a fact.

13. Scientists have discovered that people typically read text from a computer screen 25% slower than from paper.

15. The function of the eyes is to collect relevant information about the object you are looking at. This information is then sent to the brain via the optic nerve. All information is analyzed in the brain, in the visual cortex, to enable you to see objects in a complete form.

16. When crying excessively, tears flow down a straight channel directly into the nose. Apparently this is why the expression “don’t make a fool of yourself” came about.

17. The eye is rotated by 6 eye muscles. They provide eye mobility in all directions. Thanks to this, we quickly fix one point of an object after another, estimating the distance to objects.

18. Among all the sense organs, the eyes occupy a special place. Up to 80% of the information the body receives from the outside passes through the eyes.

19. It is known that Grigory Rasputin trained the expressiveness of his gaze, its rigidity and strength in order to assert himself in communication with people. And Emperor Augustus dreamed that those around him would find supernatural power in his gaze.

20. Our eye color provides information about heredity. For example, blue eye color is more common in northern regions, brown in temperate climates, and black in the equator region.

21. When exposed to daylight or too much cold, a person’s eye color can change (this is called a chameleon)

22. Today it is believed that people with dark eyes are persistent, resilient, but in crisis situations they are too irritable; gray-eyed - decisive; brown-eyed people are reserved, while blue-eyed people are hardy. Green-eyed people are stable and focused.

23. There are approximately 1% of people on Earth whose iris color is different in their left and right eyes.

24. A mechanism with a human eye - is it possible? Without a doubt! The most interesting thing is that such a device already exists! Mitsubishi Electric has developed an electronic eye on a chip that is already used in some products. This eye has the same functions as the human eye.

25. Why do people close their eyes when they kiss? Scientists have studied this interesting fact and found out that during a kiss we lower our eyelids so as not to faint from an overabundance of feelings. During a kiss, the brain experiences sensory overload, so by closing your eyes, you subconsciously reduce the excess intensity of passions.

26. Caution: When vision works under heavy overload, general overwork of the body occurs, which is tantamount to stress. Hence the headaches and feeling of fatigue. The eyes of those who work with computers are more strained than those of those who work with printed text.

27. Computers of the future can be controlled by eye movements! And not with a mouse and keyboard, as it is now. Scientists at College London are developing technology that will monitor pupil movement and analyze the mechanism of human vision.

28. The human eye distinguishes only seven primary colors - red, orange, yellow, green, blue, indigo and violet. But besides this, the eyes of an ordinary person can distinguish up to one hundred thousand shades, and the eyes of a professional (for example, an artist) up to a million shades!

29. According to experts, what makes any eyes BEAUTIFUL is internal energy, health, kindness, interest in the world around you and people!

30. Record: The Brazilian can bulge his eyes 10 mm! This man used to work at a commercial haunted attraction where he scared visitors. However, now he is seeking global recognition of his abilities. And wants to get into the Guinness Book of Records!

31. Why does vision deteriorate? Experts say that eyes are an indicator of how we look at the world. If vision deteriorates, then it is possible that a person is simply internally shutting himself off from something in his life, he is not happy with something in the world around him. Although there are, of course, other reasons for visual impairment.

32. Clothes that are too tight have a negative effect on your eyesight! It interferes with blood circulation, and this affects the eyes.

33. Man is the only creature that has whites of eyes! Even monkeys have completely black eyes. This makes the ability to determine other people's intentions and emotions by their eyes an exclusively human privilege. From the eyes of a monkey it is completely impossible to understand not only its feelings, but even the direction of its gaze.

34. Indian yogis treat their eyes by looking at the sun, stars and moon! They believe that there is no light equal in strength to that of the sun. The sun's rays revitalize vision, accelerate blood circulation, and neutralize infections. Yogis recommend looking at the sun in the morning, when it is not covered by clouds, with eyes wide open but relaxed for as long as possible or until tears appear in the eyes. This exercise is best done at sunrise or sunset. But you should not look at it at noon.

35. Greek philosophers believed that blue eyes owe their origin to fire. The Greek goddess of wisdom was often called "blue-eyed".

36. Psychologists have discovered what attracts us to strangers. It turns out that most often we are attracted to sparkling eyes that radiate some kind of emotion.

37. It’s impossible to sneeze with your eyes open!

38. The iris of the eyes, like human fingerprints, are very rarely repeated in people. We decided to use this! Along with the usual passport control, in some places there is a checkpoint that determines the identity of a person by the iris of his eye.

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We can say with confidence that vision is the most important sense of a person, since it is the eyes that provide us with up to 80% of all the information that people receive from the environment. The structure and functioning of the visual analyzer is very complex, and some nuances still remain a mystery to scientists. However, there are many interesting facts about the eyes that will certainly not leave you indifferent.

1. The retina (the light-receiving inner shell of the eye) perceives images of surrounding objects inverted, that is, a person, in fact, sees everything “upside down”, as well as in a smaller version. But in this situation, the brain comes to the rescue and “puts” the picture in its place. To see the world as our retina does, we can wear glasses with prismatic lenses.

The human eye perceives everything around in an inverted state, but the brain makes its own adjustments to this process

2. A person actually sees with his brain. The human eye, in fact, is only a means of collecting information, and we see solely thanks to the brain. The light leaves a reduced and inverted image on the retina, which is transformed from light rays into a nerve impulse. The latter, through the optic nerve, reaches the visual part of the cerebral cortex (occipital region), where the received information is deciphered, analyzed, processed, corrected, and the person perceives the image correctly.

3. All blue-eyed people have the same ancestor. The fact is that blue eye color appeared as a mutation approximately 6,000 (maximum 10,000) years ago. Until this moment, blue eyes simply did not exist in humans. Changes occurred in the OCA2 gene, which is responsible for the process of melanin synthesis (the pigment on which the color of human eyes depends). Researchers, after conducting several experiments and studies, came to the conclusion that the first person who received blue eyes as a gift from nature lived on the Black Sea coast. Exactly how the mutation spread throughout the world remains a mystery, but today approximately 40% of Caucasians are blue-eyed.

Interesting fact: all people with blue eyes come from the same ancestor

4. There are people with different eye colors. This situation is not considered a disease, but is a deviation in normal development and occurs in approximately 1% of people, called heterochromia. Heterochromia develops due to a violation of melanin synthesis in the iris of the eye. Most often it is hereditary, but can occur due to previous injuries and certain ailments. There is also a partial form of heterochromia, in which case part of the iris is, for example, brown in color, and at the same time there are islands of gray color.

Option of complete and partial heterochromia of eye color

5. Eyebrows serve a protective function.. Many people don’t even know why a person needs eyebrows. However, they serve an important role. They protect the eyes from possible sweat that flows from the forehead. Sweat contains large amounts of salt, which can damage the delicate structures of the eye. The thicker the eyebrows, the better the eyes are protected.

6. Everyone's eyeball size is the same. Regardless of status, age, race, physique, the size of the eye in all people is almost equal and corresponds to 24 mm. It is also interesting that in small children it is almost the same, so the eyes of children seem large and expressive.

The size of the eyeball is the same in almost all people

7. The fastest reflex in the body is blinking. The muscle that is responsible for eyelid movements is the fastest. To implement the blink reflex, our body needs only 10-30 ms, which is an absolute record.

8. The lens is many times superior to even the fastest and highest quality photographic lens in the world. To understand this, it is enough to realize how many objects a person immediately focuses his gaze on. The change of focus occurs before you even move your gaze to the next object. No camera can do this; even the best lens takes seconds to change focus.

9. Visual acuity is more than 100% (or 1.0). Anyone who has ever been to an ophthalmologist is familiar with the procedure for checking vision using special tables. Typically they have 10 lines of letters or images. If a person sees the last line from a distance of 5 m, then his vision is considered ideal and equals 1.0 (100%). But in fact, there are individuals whose eyes can be even more keen and see, for example, 120%.

Visual acuity of one is far from the limit for a person

10. Colorblindness predominantly affects males., and every 12 men may not distinguish one or more colors, and most of them are not even aware of their peculiarity. Color blindness is a genetic defect that is passed on the X chromosome from a carrier mother to her son. This is why men have an increased risk factor for color blindness, since they do not have a “spare” healthy X chromosome, unlike women.

11. Peripheral vision in women is much better developed than in men. This is due to the peculiarities of human evolution. Since ancient times, a woman’s main task was caring for children, preparing food and other household chores (often it was necessary to take care of everything at the same time). The men were focused on hunting and looked only at the center. By the way, such an interesting fact about the vision of men and women was described quite recently. A woman, looking straight, sees much more with her peripheral vision than the stronger sex.

Women see much better with peripheral vision than men

12. Newborn children see very poorly only at a distance of 30-40 cm. This is exactly the distance at which the mother's face is when breastfeeding. That is why the first person a baby begins to recognize is his mother.

13. Eye muscles are the most “hard-working” in the body. These small muscle fibers are more active than any other muscle in the body. They almost never rest, because even in sleep a person moves his eyeballs.

14. Ommatophobia – fear of eyes. There are a lot of strange and little-studied phobias in the world, and ommatophobia is considered one of these. An ommatophobic person cannot look another person in the eye due to fear. Such people never look others in the eye, wear deep hoods, and wear dark glasses. Fortunately, this phobia is rare and most often manifests itself in an erased form. Patients are treated by a psychotherapist. As soon as it becomes clear what exact reasons became the basis for ommatophobia, getting rid of it becomes easy.

People suffering from ommatophobia are afraid of the eyes

15. Brown eyes are actually blue, but underneath a layer of pigment.. Everyone knows that children are born with the same eye color - dirty blue, and at about 3-5 months of life the iris acquires its final color - brown, green, blue, black, etc. The fact is that pigment cells begin to synthesize that amount melanin, which is embedded in the genetic code, and the eyes change color. But if your iris is brown, then you can easily change its color to blue. For this purpose, there is a special laser operation that reduces the amount of pigment and the originally blue tint appears.

16. The pattern of a person's iris is as unique as a fingerprint.. There are no two identical individuals in this parameter. Therefore, it can be used for identification, for example, when going through passport control.

The iris pattern, like fingerprints, is unique to each person.

17. It’s impossible to sneeze with your eyes open.. Scientists explain this as a reflex response - when sneezing, the facial muscles of the face contract, including the orbicularis oculi muscle. This action is associated with a protective function - closing the eyelids when sneezing prevents microorganisms from entering the eyes that fly out of the mouth.

18. The rarest eye color in nature is green.. According to statistics, only 2% of the planet's population have a green iris of various shades (from gray-green to emerald). It is also interesting that the medieval Inquisition considered red-haired women with green eyes to be witches and burned them at the stake. This also influenced the low prevalence of such a beautiful color in our time.

Thus, there are many amazing facts about human eyes and this is only a small part of them. It is not for nothing that they say that the eyes are the mirror of the human soul, and the soul is the greatest secret of our world.

- a very important organ in the human body, thanks to which a person perceives 95% of the information received. But there are many other interesting facts associated with eyes and vision.

All eye cells are sensitive to sunlight, and there are 107 million of them in each eye.
The human eye can distinguish about five hundred shades of gray.
Unlike the ears and nose, which grow throughout life, the size of the eyes remains unchanged from birth.
A person blinks at a speed of about one hundred milliseconds; this muscle is the fastest in the body.
The diameter of the eye is on average about two and a half centimeters, and the weight is only about eight grams.
The corneas of a human and a shark are very identical. That is why the latter is used as a substitute for eye surgery.
The eyes are the most resource-intensive part of the body for an organ. It uses 65% of the total work of all organs.
The average lifespan of an eyelash is about 5 months.
Ten thousand years ago, absolutely all people on the planet had brown eyes. However, a genetic mutation soon appeared that led to the appearance of blue eyes.
Those same wriggling particles that are clearly visible if you look at a bright, monochromatic space are called “floating clouds.” They occur because the strands of white in the eye cast shadows.
The octopus is the only animal on the planet that does not have a blind spot.
In ancient times, some peoples, such as the Mayan Indians, considered strabismus attractive and, in order to specifically obtain it, they had to perform certain exercises.
Eyes began to evolve more than 500 million years ago from particles of photoreceptor proteins in the simplest unicellular organisms.
Very often, poor vision is associated with problems in the visual cortex of the brain, and not with the eyes.
The eyes can focus on 50 objects per second.
Human vision sees all images upside down; they return to their normal position in the brain.
The eyes perceive only 3 colors: red, green and blue. The remaining colors and shades are created by mixing these three.
The eye movement test can diagnose schizophrenia with very high accuracy.
We see only colors from the visible spectrum, since only they are able to penetrate water - the medium from which eyes began to evolve.
There is a very rare genetic mutation in women that allows them to see about a hundred million flowers.
The iris has 256 unique characteristics, which is 6.4 times more than fingerprints.
The pupils involuntarily dilate when a person looks at something he likes.
More than 8% of men are colorblind.
The eyes can only make smooth movements while following a moving object.
Those bright flashes that occur when you rub your eyes are called “phosphene.”
The visible part of the eyeball is one-sixth of its total size.
A person cannot cry in space, because due to the lack of gravity, tears accumulate into balls and cannot roll down.
At birth, everyone has the same blue-gray eye color, and after 2 years, depending on the concentration of the melanin pigment, the true color appears.
People with green eyes are the owners of the rarest color. And the red color of the iris in albinos is explained by the lack of pigment and blood vessels, which therefore become visible.
At the moment, it is not possible to perform a complete eye transplant due to its close connection to the brain. The optic nerve also cannot be restored.

How do people and animals perceive color?

Cats cannot access the color red and they see the world around them as not bright at all, but they can distinguish as many as 25 shades of gray. After all, when hunting mice, it is very important for them to accurately determine their color.
Dogs cannot distinguish red, orange and yellow at all, but they clearly see blue and purple.
The rarest eye color in humans is green. Only 2% of our planet's population can boast of it.
A person is born with conditionally light gray eyes, and their “true” color appears by 2-3 years.
Thanks to the huge number of light-sensitive cells - more than 130 million - the human eye is able to perceive about 5 million color shades.
The bee does not see red and confuses it with green, gray and even black. She clearly distinguishes only yellow, blue-green, blue, purple, violet. But it perceives ultraviolet radiation very well. Bright blue-violet patterns can be seen among the pale, white petals, indicating where to look for nectar.
Eye color depends on a pigment in the iris called melanin. A large amount of pigment determines the formation of the dark color of the iris (black, brown, light brown), and a smaller amount determines the formation of light colors (gray, green, blue).
Unlike most animals, humans have three basic perceived colors - red, blue and green, which when mixed produce all the colors visible to the eye.
Red eye color is found only in albinos. It is associated with the complete absence of melanin in the iris, and is therefore determined by the blood in the vessels of the iris.
Contrary to popular belief, cows and bulls do not distinguish between the color red. Many are sure that during a bullfight, the bull is irritated by the toreodore's cloak, but as it turns out, this is not the case. The bull is provoked not by the color, since he does not see red, but by the very fact of movement. Since bulls are also myopic, the flickering of a rag is understood by them as a challenge and aggression from the enemy.
For 1% of people on Earth, the color of the iris of the left and right eyes is not the same.
It is generally accepted that color blindness is a purely male “fate.” About 8% of men and only 1% of women suffer from it to one degree or another.
Residents of the Baltic states, northern Poland, Finland and Sweden are considered the brightest-eyed Europeans. And the largest number of people with dark eyes live in Turkey and Portugal.

I'm looking far away!

Dogs see well at a distance, no closer than 35-50 cm. And closer objects look blurry and shapeless to them. A dog's visual acuity is approximately one-third that of a human. But their eyes are tripled in such a way that they can easily determine the distance to an object.
The dragonfly is the most vigilant representative of insects. She can distinguish objects the size of a small bead at a distance of 1 m. A dragonfly's eye is made up of 30,000 individual ocelli, these eyes are called "compound" eyes. Each of them snatches one point from the surrounding space, and in her brain everything is put together into a single mosaic. It's hard to imagine, but a dragonfly's eye perceives up to 300 images per second. In cases where a person sees a flickering shadow, the dragonfly will clearly see a moving object.
If we take an eagle's visual acuity to be 100%, then normal human vision is only 52% of an eagle's vision.
The falcon is able to see a target 10 cm in size from a height of 1.5 km.
The vulture distinguishes small rodents from a distance of up to 5 kilometers.
Frogs only see moving objects. To look at a stationary object, she herself needs to start moving. In a frog, almost 95% of visual information enters immediately into the reflex department, that is, seeing a moving object, the frog reacts to it with lightning speed, as if it were potential food.
In humans, the viewing angle is 160 to 210°.
Goats and bison have horizontal and rectangular pupils. Such pupils expand their field of view to 240°. They see almost everything around, in the literal sense of the word.
The horse's eyes are positioned so that its vision is 350°. Their visual acuity is almost the same as that of humans.
A cat has a viewing angle of 185°, while a dog has only 30-40°.

Who sees best in the dark?

The most famous bird with good night vision is the owl.
Cats see in the dark 6 times better than humans. In the dark, their pupils noticeably dilate, reaching a diameter of 14 mm, but on a bright sunny day they narrow, turning into thin slits. This is because too much light can damage the sensitive cells in the retina, and with such narrow pupils, a cat's eyes are well protected from the bright rays of the sun. For comparison, in humans the maximum pupil diameter does not exceed 8 millimeters.
Owls are awake at night and see much better at night than during the day. On a moonless night, they can easily spot a mouse sneaking through the grass, a bird hiding among the leaves, or a squirrel climbing a shaggy spruce tree. During the day, owls see poorly and wait until dusk in a secluded corner.
Horses have good panoramic vision, a developed ability to see in the dark and judge the distance to objects. The only thing in which horses' vision is inferior to humans is color perception.

Eyes and their features

The chameleon's eye movements are completely independent of each other: one can look forward, the other can look to the side.
Some species of scorpions have up to 12 eyes, and many spiders have eight. The famous New Zealand lizard tuatara, which is considered a contemporary of dinosaurs, is called “three-eyed”. Her third eye is in her forehead!
The diameter of the adult human eyeball is about 24 millimeters. It is the same for all people, differing only in fractions of a millimeter (without the presence of eye pathologies).
Goats, sheep, mongooses and octopuses have rectangular pupils.
An ostrich's eyes are larger in volume than its brain.
Jumping spiders have eight eyes - two large and six small.
The eyeballs of an owl occupy almost the entire skull and, due to their large size, they cannot rotate in their orbits. But this drawback is compensated by the exceptional mobility of the cervical vertebrae - the owl can turn its head 180°.
Sea stars have one eye at the end of each ray and individual light-sensitive cells are scattered over the entire surface of the body, but these sea inhabitants are only able to distinguish between light and dark.
The eye of large whales weighs about 1 kg.
The pattern of a person's iris is individual. It can be used to identify a person.
The eyes of a mantis shrimp are a complex system. At the same time, they see in optical, infrared, ultraviolet, and also in polarized light. In order for a person to see in all these ranges, he needs to carry about 100 kg. various electronic equipment.
Among the inhabitants of the seas, the most perfect eyes are found in cephalopods - octopuses, squids, and cuttlefish.

Do you know that...

On average, a person blinks every 10 seconds, blinking time is 1-3 seconds. It can be calculated that in 12 hours a person blinks for 25 minutes.
Women blink about twice as often as men.
A person has 150 eyelashes on the upper and lower eyelids.
On average, women cry 47 times a year, and men - 7.
It is impossible to sneeze with your eyes open.
When working at a computer during the day, the eyes focus from the screen to the paper about twenty thousand times.
Crocodiles cry when eating meat. Thus, through special glands near the eyes, they remove excess salts from the body. This fact was experimentally confirmed by American scientists.
The eyes get used to the dark in 60-80 minutes. After being in the dark for about a minute, sensitivity to light increases 10 times, and after 20 minutes - 6 thousand times. That is why, when we go out into the light after being in a dark room, we always feel severe discomfort.