Eagle vision in humans. Eagles have the best vision on earth

Instructions

Eagles have the most better vision not only among birds, but among all living creatures on Earth. Eagles see not only clearer and farther, but also brighter. In addition, they distinguish ultra-violet rays. Job eagle eye some scientists compare it to the functioning of a telephoto lens.

If a person had eagle vision, he could see the expressions on the faces of theater actors, sitting in the last row in the hall, and insects crawling on the ground, being on the tenth floor of the building.

As a result of numerous experiments, it was found that the retina of the eyes of eagles is designed in such a way that they are able to perceive more light than humans and all other creatures. This allows them to distinguish more small details. The kite notices carrion lying on the ground from a height of 2000 meters.

Like humans, eagles have binocular vision and focus quickly. Moreover, their viewing angle is much greater than that of humans and amounts to as much as 275 degrees. They have excellent spatial orientation and are able to determine the location of prey located several kilometers away from them. The panoramic vision of eagles covers an area of more than 7 square kilometers.

It is curious that the vision of these phenomenal birds, among other things, develops as they grow older.

As for the structure of the eyes, in addition to a pair of eyelids that protect the retina during rest, eagles have so-called nictitating membranes that protect the eyes during flight from the pressure of wind, bright sun and dust.

Another one characteristic feature Eagles, as well as many other birds, have two “yellow spots” in the fundus. The "yellow spot" is the point where greatest number photosensitive cells(rods and cones). Two such spots give the birds an undeniable advantage. Eagles see two objects equally clearly, located at a decent distance from each other.

Birds - beautiful creatures nature. People have long envied their ability to fly, but birds have another feature that people could admire. It's theirs amazing vision.

Instructions

Vision plays a huge role in the life of birds. Many birds have to simultaneously hunt down prey and carefully watch so as not to become someone's lunch. Others look for their victims on the sky, while they themselves are high in the sky. Still others are nocturnal and see perfectly in the dark. Therefore, during the course of evolution, vision in birds has developed much more than in birds.

Birds see four to five times sharper than. Most people have monocular vision (the exception is owls) - that is, they perceive primarily with one eye. But their field of view itself is much wider than that of, and is about 300 degrees. This is achieved due to the location of the eyes - in birds they are on the sides. And the structure visual organ The nightjar allows him to see 360 degrees without turning his head at all.

A person has a yellow spot in the middle of the fundus of the eye - the place where maximum concentration is observed

So, you have the things required according to the instructions, so it’s time to start.

Step 2

Actually, everything is simple. We sit in front of the mirror and look into the “third eye” zone. No, we’re not just looking, as you probably thought. We define the third eye as follows: take a mirror and look at the point above the nose. You are looking? Now we gradually bring the mirror to our face. You will see that the outlines of two eyes have appeared above the eyes. We continue to bring the mirror up and see that two “ghost eyes” have formed one. It is located approximately above the bridge of the nose. If you received desired effect, then move on to the next step.

Step 3

So, let's remember the place of the third eye. Do you remember? Now we come to the mirror. It is better to take a large mirror. We sit down and direct our gaze to the third eye point. Your task is to find a state of gaze where you can look into the third eye area for 15 minutes without blinking. This is the eagle's gaze. Don't try to get this effect right away. This may take three weeks. And this is in best case scenario. But the result is worth it. You will feel much more cheerful, energetic and generally in an awesome state. Remember, your job is to find the eagle eye, not to train it, so don't force yourself to look in the mirror. This is very important aspect instructions.

Don’t overdo it: You can devote 20 minutes a day to searching for such focus, but it’s not worth it.
Remember it is your choice.
Remember that staring at one point for too long is bad for your eyes, so it's up to you to decide whether you need it or not. Good luck!

I continue to look for outstanding visual acuity scores. I talked about the most vigilant man on Earth. However, this person’s vision cannot even be called “good” when compared with an eagle.

What kind of bird is an eagle?

Unique visual acuity indicators cannot be achieved without specific features structure of the eye. Big size the eye allows a larger image to be reflected on the retina. In addition, a higher density of light-sensitive cells (rods and cones) makes the image clearer and more detailed. In each eye, the eagle has two central foveae (areas of maximum concentration of receptors), which also make a significant contribution to the eagle's unique vision.

To protect their vision, eagles have two pairs of eyelids. One of which the bird uses on the ground or while stationary. The second pair of eyelids is necessary for the eagle to protect itself in the air. First of all, they protect well from air pressure, because the diving speed of an eagle reaches 100 km/h. This extra pair of eyelids covers the eye to keep it clear and unclouded.

Like humans, the eagle has binocular vision. In addition, accommodation (focusing) occurs very quickly. Others are very unusual property for living nature is the ability of this bird to distinguish colors. This ability is developed in them to a greater extent than in people, which is why our planet looks more colorful from the eyes of an eagle. Due to the fact that the bird's eyes are located far from each other, it has a good sense of the depth of space (height and distance). This property is vital when diving. Another interesting fact is that an eagle’s vision develops gradually as it grows older.

Eagle vision in numbers

The width of the eagle's field of vision is 275 degrees, due to which it clearly sees what is happening behind it. The eagle's vision is capable of identifying prey from a distance of two kilometers, but if the bird helps by moving its head, then this distance can double. In search of prey, an eagle can scan an area of 13 square meters with great care. km.

It seems to us that animals see the world in much the same way as we do. In fact, their perception is very different from that of humans. Even in birds - warm-blooded terrestrial vertebrates, like us - the senses work differently than in humans.

Vision plays an important role in the life of birds. Someone who can fly needs to navigate the flight, notice food in time, often at a great distance, or a predator (which, perhaps, can also fly and is approaching quickly). So how does bird vision differ from human vision?

To begin with, we note that birds have very large eyes. Thus, in the ostrich their axial length is twice that of human eye, - 50 mm, almost like tennis balls! In herbivorous birds, the eyes make up 0.2–0.6% of the body weight, and in birds of prey, owls and other birds that look out for prey from afar, the mass of the eyes can be two to three times greater than the mass of the brain and reaches 3–4% of the body weight. for owls - up to 5%. For comparison: in an adult, the mass of the eyes is approximately 0.02% of the body mass, or 1% of the mass of the head. And, for example, in a starling, 15% of the mass of the head is in the eyes, in owls - up to a third.

Visual acuity in birds is much higher than in humans - 4–5 times, in some species, probably up to 8. Vultures feeding on carrion see the corpse of an ungulate animal 3–4 km away from them. Eagles spot prey from a distance of about 3 km, large species Sokolov - from a distance of up to 1 km. And the kestrel falcon, flying at an altitude of 10–40 m, sees not only mice, but even insects in the grass.

What structural features of the eyes provide such visual acuity? One factor is size: larger eyes allow larger images to be captured on the retina. In addition, the bird's retina has a high density of photoreceptors. People in the zone of maximum density have 150,000–240,000 photoreceptors per mm2, the house sparrow has 400,000, and the common buzzard has up to a million. In addition, good image resolution is determined by the ratio of the number of nerve ganglia to receptors. (If multiple receptors are connected to a single ganglion, the resolution is reduced.) In birds this ratio is much higher than in humans. For example, in the white wagtail there are about 100,000 ganglion cells for every 120,000 photoreceptors.

Like mammals, birds' retinas have an area called the fovea, a depression in the middle macular spot. IN fovea because of high density receptors, visual acuity is the highest. But it is interesting that 54% of bird species - raptors, kingfishers, hummingbirds, swallows, etc. - have another area with the highest visual acuity to improve lateral vision. It is more difficult for swifts to forage than for swallows, partly because they have only one area acute vision: Swifts see well only forward, and their methods of catching insects in flight are less varied.

The eyes of most birds are located quite far from each other. The field of view of each eye is 150–170°, but the overlap of the fields of both eyes (field of binocular vision) is only 20–30° in many birds. But a flying bird can see what is happening in front of it, from the sides, behind and even below (Fig. 1). For example, the large and bulging eyes of American woodcock Scolopax minor They are located high on a narrow head, and their field of vision reaches 360° in the horizontal plane and 180° in the vertical. The woodcock has a field of binocular vision not only in front, but also behind! Very useful quality: a feeding woodcock thrusts its beak into the soft ground, looking for earthworms, insects, their larvae and other suitable food, at the same time he sees what is going on around him. Big eyes nightjars are slightly shifted back, their field of view is also about 360°. A wide field of view is characteristic of pigeons, ducks and many other birds.

And in herons and bitterns, the field of binocular vision is shifted downwards, under the beak: it is narrow in the horizontal plane, but extended vertically, up to 170°. Such a bird, when holding its beak horizontally, can see its own paws with binocular vision. And even raising its beak upward (as a bittern does when waiting for prey in the reeds and camouflaging itself with vertical stripes on its plumage), it is able to look down, notice small animals swimming in the water and catch them with precise throws. After all binocular vision allows you to determine the distance to objects.

For many birds, it is more important not to have a large field of view, but rather to have good binocular vision with both eyes at once. These are primarily birds of prey and owls, as they need to judge the distance to their prey. Their eyes are close-set, and the intersection of their visual fields is quite wide. In this case, the narrow overall field of view is compensated by neck mobility. Of all bird species, owls have the best developed binocular vision, and they can turn their heads 270°.

To focus the eyes on an object during rapid movement (either its own, or the object’s, or total), good accommodation of the lens is needed, that is, the ability to quickly and strongly change its curvature. Birds' eyes are equipped with a special muscle that changes the shape of the lens more effectively than in mammals. This ability is especially developed in birds that catch prey underwater - cormorants and kingfishers. Cormorants have an accommodation capacity of 40–50 diopters, and humans have 14–15 diopters, although some species, such as chickens and pigeons, have only 8–12 diopters. Diving birds are also helped to see under water by the transparent third eyelid that covers the eye - a kind of goggles for scuba diving.

Everyone has probably noticed how brightly colored many birds are. Some species - redpolls, linnets, robins - are generally dimly colored, but have areas of bright plumage. Others develop brightly colored body parts during the mating season, for example, male frigatebirds inflate a red throat sac, and puffins have a bright orange beak. Thus, even by the color of the birds it is clear that they have well-developed color vision, unlike most mammals, among which there are no such elegant creatures. Among mammals, primates are the best at distinguishing colors, but birds are ahead of even them, including humans. This is due to some structural features of the eyes.

There are two main types of photoreceptors in the retina of mammals and birds - rods and cones. Rods provide night vision; they dominate the eyes of owls. Cones are responsible for daytime vision and color discrimination. Primates have three types (they perceive red, green and blue colors), other mammals have only two. Birds have four types of cones with different visual pigments - red, green, blue and violet/ultraviolet. And the more varieties of cones, the more shades the eye can distinguish (Fig. 2).

Unlike mammals, each cone of birds contains another drop of colored oil. These drops play the role of filters - they cut off part of the spectrum perceived by a particular cone, thereby reducing the overlap of reactions between cones containing different pigments, and increasing the number of colors that birds can distinguish. Six types have been identified in cones oil drops; Five of them are mixtures of carotenoids that absorb waves of varying lengths and intensities, and the sixth type lacks pigments. The exact composition and color of the droplets varies from species to species: perhaps they provide fine-tuning of vision so that its capabilities the best way corresponded to their habitat and feeding behavior.

The fourth type of cones allows many birds to distinguish ultraviolet color, invisible to humans. The list of species for which this ability has been experimentally proven has grown significantly over the past 35 years. These are, for example, ratites, waders, gulls, auks, trogons, parrots and passerines. Experiments have shown that the areas of plumage displayed by birds during courtship often have ultraviolet coloration. To the human eye, about 60% of bird species are not sexually dimorphic, meaning males and females are indistinguishable in appearance, but the birds themselves may not think so. Of course, it is impossible to show people how birds see each other, but you can roughly imagine this from photographs where ultraviolet areas are tinted with a conventional color (Fig. 3).

The ability to see ultraviolet color helps birds find food. Fruits and berries have been shown to reflect ultraviolet rays, making them more visible to many birds. And kestrels may see the paths of voles: they are marked with urine and excrement, which reflect ultraviolet radiation and thereby become visible to the bird of prey.

However, although birds have the best color perception among terrestrial vertebrates, they lose it at dusk. To distinguish colors, birds need 5–20 times more light than humans.

But that is not all. Birds have other abilities that are not available to us. So, they see fast movements significantly better than people. We do not notice flickering at a speed greater than 50 Hz (for example, the glow fluorescent lamp seems continuous to us). Temporary O e visual resolution in birds is much higher: they can notice more than 100 changes per second, for example, in the pied flycatcher - 146 Hz (Jannika E. Boström et al. Ultra-Rapid Vision in Birds // PLoS ONE, 2016, 11(3): e0151099, doi: 10.1371/journal.pone.0151099). It makes it easier small birds hunting insects, but perhaps makes life in captivity unbearable: the lamps in the room, in the opinion of a person, are normally luminous, but for the bird they flicker disgustingly. Birds are also able to see very slow movement - for example, the movement of the sun and stars across the sky, inaccessible to our naked eye. It is assumed that this helps them navigate during flights.

Colors and shades unknown to us; all-round view; switching modes from “binoculars” to “magnifying glass”; the fastest movements are clearly visible, as if in slow motion... It is difficult for us to even imagine how birds perceive the world. One can only admire their capabilities!

I see that I can’t see well) I don’t wear glasses, but I can’t see the number of a minibus approaching in the distance, although I could do it before) And the reluctance to see poorly motivates me to correct this situation. So, there is a goal, now we need to decide on ways to achieve it. While flipping through the goals on this site, I came across a similar goal and in general I liked one system for improving vision, here’s the author. I will try to complete the entire course, and this site will be my progress log.

Goal Accomplishment Criteria

Reading the bottom line of the table for a vision test at a distance of 5 meters

Personal resources

I have free time, accordingly, it is possible to perform the exercises the required number of times. there is a clear algorithm of actions. there is this site where I publicly declare my goal, and this increases my responsibility for achieving it.

Goal ecological compatibility

I feel discomfort when I notice that I can’t read something in the distance. I want to enjoy clear vision

Week #1

1. PALMING(from the English palm - palm) - the most important exercise for relaxing the oculomotor muscles. Performed WITHOUT GLASSES.

Rub your palms together until warm. Place the fingers of each hand tightly together. As if you want to water the birds from your palms, and so that the water does not spill between your fingers. The fingers of one palm overlap the fingers of the other at right angles. And we put this design on our eyes instead of glasses (see photo in a circle), so that the crossed fingers are in the center of the forehead, the nose sticks out between the bases of the little fingers, and the eyes fall exactly in the center of the dimples of your palms. The nose breathes freely and is not pinched. Eyes closed. The palms are pressed tightly to the face - no gaps so that the light does not reach the eyes. Place your elbows on or pressed to your chest. The main thing is that the elbows are not suspended, and the head is a direct continuation of the back.

Another important palming exercise is a pleasant memory.

Every time, think about something good, something good that happened in your life.

Exit from palming. They sat up straight, closed their eyes slightly under their palms - loosened, closed their eyes - loosened, closed their eyes - loosened. The palms were removed. WITH eyes closed shook your head slightly and restored blood supply to the brain. Like children, they gently “wet” their eyes with their fists and wiped them. We sighed. We exhaled. And we open our eyes, blinking quickly.

Whenever you feel tired, eye strain when reading, working on a computer, watching TV, etc., put everything aside, rub your palms until warm and do palming. Three to five minutes.

Ideally - every hour when working on.

Palming can and is beneficial for EVERYONE!

2. CHARGING

1. Raised our eyes up, down, up, down, up, down. Blinked, blinked, blinked.

2. They squinted their eyes to the right, left, right, left, right, left. They blinked.

3. "Diagonal". We look up right - down left, up right - down left, up right - down left. They blinked. Reverse "diagonal". Left up - right down. The same 3 times. They blinked.

4. "Rectangle". We raised our eyes upward, “drew” the top side of the rectangle, the right side, the bottom, the left side, the top again, and so on 3 times in a row. They blinked. IN reverse side“draw” a rectangle (counterclockwise). Top side, side left, bottom, right. 3 times. They blinked.

5. "Dial". Imagine there is a huge dial in front of you. You look around it clockwise. We raised our eyes to 12 o'clock - 3 o'clock, 6, 9, 12. And so 3 circles. They blinked. In the opposite direction “Dial”. We looked up at 12 o'clock, 9, 6, 3, 12... 3 laps. They blinked.

6. “Snake”. Let's start drawing from the tail. Eyes left down - up, down - up, down - up and head. They blinked. Back. From the head of the "snake". Down - top, down - up, down - up and tail. They blinked.

Repeat 3 times a day.

3. Breaks every hour of working at the computer or reading
4. Sunday
Week #2

Exercise "Central fixation":

You need to focus on an object in the distance, then on an object near. That is, for example, we look out the window, look at the house opposite, then focus on the point window frame which is in front of us, and so on several times.

Exactly the same step-by-step “peering” can be done with other objects that have nesting. For example, book -> line -> word -> letter.

Now charging. The previous exercises still need to be performed, and 6 more exercises are added to them:
1. "Bow". First, squint your eyes to one of the lower corners, then vertically up, diagonally down, vertically up, diagonally down. This is how a bow, or an angular figure eight, or inverted hourglass) You need to outline 3 bows.
2. "Hourglass". The same as the bow exercise, only inverted.
3. "Spiral". Focus your eyes on the nose, and then begin to outline a spiral from the nose to the ceiling and walls, 3 curls in total.
4. Horizontal "spiral". You need to imagine a horizontal pipe in front of you and, as it were, “wind turns around it with your eyes. From left to right there are 5 turns and back 5.
5. Vertical "spiral". The same as the previous exercise, but now you need to wind the turns onto a vertically standing pipe.
6. "Globe". You need to rotate the globe along the equator with your eyes) In this exercise you can move your head, ears, hair...
This week, 5 exercises of the first stage must be repeated 5 times, and don’t forget about breaks and palming.
Week #3

This week it's time to put yourself in stricter limits! Palming - not when your eyes are tired, but 5-6 times a day! Even if your eyes are tired only 3 times! Central fixation - 10 times! Exercise - 4 times a day!

Charger:

It is carried out exactly the same as in the second week, all exercises are saved, no new ones appear;

The first three days of exercises up to the “snake” are done 6 times, the rest, starting with the “snake”, maintain their number;

For the next 3 days, exercises up to the “snake” are done 7 times, the rest keep the same number.

As you know, the eyes also require an influx of oxygen supplied by the blood. Therefore for comprehensive health improvement eyes should also be concerned about blood flow to the head. To do this, it is enough to do various head tilts in the morning and evening 4-5 times each (like in physical exercise, when you start warming up). This is good not only for the eyes, but also for the brain.
Week #4

Palming - 5 - 6 times daily,

Central fixation - 10.

Eye exercise - 4 times a day. Monday - Wednesday: repeat exercises 1-5 7 times. Thursday - Saturday: 8 times. Exercises 6 - 12 - ONE time. Sunday is a day off.
Week #5

Palming - 5 - 6 times daily, central fixation - 10.

Exercise for the eyes - 5 times a day.

Monday - Saturday: I repeat the first FIVE exercises 8 times. Exercises 6 - 12 - only ONE time. Sunday is a day off.

New exercises:

1. Spray your eyes with cold boiled water

It’s better to melt it, advises the professor. - Boil water, freeze in the refrigerator. Then wash your face with thawed water and splash it into your OPEN eyes in the morning and evening. Water retains its polymer structure as long as ice crystals remain in it.

Why pre-boil? To remove bleach. Bleach eats your eyes. Therefore, tap water must be left to stand and boiled so that the chlorine evaporates...

2. Make faces

Very useful exercise: take off your glasses, tense and relax all the muscles of your face - move your jaws, ears, eyes. Make funny (!) faces in front of the mirror. The better developed all the facial muscles are, the more efficiently they work. oculomotor muscles and blood supply to the eyes improves. Note: infants They lie on their backs and constantly grimace involuntarily. They instinctively tense and relax their facial muscles so that they develop.
Week #6

I play pirates

- “One-Eyed Glasses” is one of the most powerful and effective exercises to restore vision,” says Professor Zhdanov. - Allows you to preserve and develop your vision even when watching TV or working. But also very difficult. That's why I never suggest it to beginners. First, you need to train the eye muscles with regular exercises, “mark on glass”, “butterfly flight”, learn to relax them with palming, solarization. And only then can you take up the “pirate glasses”. The trick is simple. You need two pairs of any frames without glass. Maybe from old glasses. You tie it at one frame right side with a thick black curtain or wrap it with opaque tape. The second one has the left one. It is possible to manipulate one frame by dragging the headband from right to left, but this is a hassle.

And wear these “one-eyed glasses” at home, in nature, on vacation, read, write, work on the computer, watch TV. No MORE than 30 minutes! A powerful load occurs when one eye is forced to work for two. But a great workout. After half an hour, close your eyes, take off your glasses, palming until the visual tract completely calms down. Then change the patch to the other eye. After another half hour, take off your “one-eyed glasses,” do palming and take a break for an hour: stay without glasses. If possible, repeat this exercise 2 - 3 times a day.

The eye under the bandage, of course, is open all the time, he is also training...

If someone who is nearsighted cannot yet see the TV screen without glasses, there is no need to suffer. Take glasses with weaker lenses and watch a TV show in them, still covering one eye with an eye patch for half an hour. Then - another. After palming.

It is very important to perform exercises with “pirate glasses” in cases of difference of eyes, when one eye sees worse than the other. In this case, give more visual work to the weak eye, that is, first of all, cover it with a “curtain” strong eye. Disagreement is dangerous because weak eye begins to interfere with the strong. This can lead to squint.