Is it possible to dive with your eyes open? Is it possible to open your eyes under water? Use of aids

Many people, while swimming at home in the bathtub, in the pool or plunging into various bodies of water, have repeatedly tried to open their eyes under water. If this happens in a clean fresh water, then there will be no harm to the visual organs. Diving into the sea can cause a burning sensation in the eyes as it contains salt. If the substance content is low, then there is no health hazard. But, for example, in the Dead Sea it is strictly advised not to open your eyes. This can result in damage to the cornea. It is unsafe to dive in polluted waters, where the mucous membranes are exposed to pathogenic organisms.

How does this or that water affect the eyes?

Bathing in the tap

For the purpose of disinfection, such water is subjected to chlorination, which can become cause of lung irritation of the mucous membranes of the eyes, and for those who are sensitive to chlorine, the residual products of such a procedure can cause reactive conjunctivitis. If the water is not well disinfected or due to severe wear and tear of the water supply system, harmful bacteria can get on the organs of vision and cause an inflammatory process. That's why long stay With with open eyes not recommended in such water. It can only be used for washing when there is short-term contact with the eyes.

Diving in freshwater bodies

Diving with your eyes open on city beaches is dangerous to your health.

Even ordinary swimming in rivers and lakes that are located near large cities can be a risky adventure, since such sources are saturated with such pathogenic bacteria, like streptococci, coli and staphylococci. It is impossible to open your eyes under water under such conditions - in these reservoirs the environment is usually turbid, and sewage with various chemicals, it's hard to see anything there. And for the organs of vision, which are much more sensitive than the skin, immersion in water is dangerous for the development of infectious diseases.

Only if you have absolute confidence in the purity and safety of the water of the river or lake where you are diving, you can open your eyes for a while.

Swimming in the pool

Swimming in chlorinated pool water is dangerous even for sensitive skin, not to mention the mucous membranes. Since such public places visits a huge number of people, chlorine is used to disinfect them from microorganisms high concentration, which can negatively affect the eyes and even provoke reactive conjunctivitis. Both bleach and those microorganisms that remain insensitive to its effects are an explosive mixture, which can cause infection and inflammatory processes organs of vision. And you don’t even need to dive to do this, just get the splashes into your eyes. One thing is clear: you should always protect them with goggles or a mask when swimming in pools.

Diving in sea water

In the Black Sea it is safe and comfortable to open your eyes underwater.

The concentration of salt in the various seas of our planet is not uniform. Thus, in the Black and Baltic seas the parameter is almost equal to the sodium chloride content in human body. Therefore in sea ​​water diving should not cause any discomfort to a person. It is only advisable to follow the recommendations of experienced divers.

People tend to show a lot of curiosity to find out what happens under water. When all the oceans had been explored and mapped, explorers turned their attention to their depths and began to descend deeper and deeper. Any person sometimes wants to open his eyes under water, even in a simple pool, when he knows perfectly well that his eyes will sting because of the chlorine. However, there are some tricks that can be used to get used to the discomfort experienced, but there are also quite reasonable precautions, since trying to see the underwater world with the naked eye can lead to unpleasant consequences for vision. Whether you're in a pool, on the sea or in a lake, to satisfy your natural curiosity and look under the water, it's usually recommended to use special swimming goggles or a mask.

Steps

Naked vision underwater

Underwater vision in the pool. Looking underwater seems simple, but anyone who has done this in a pool with highly chlorinated water knows how it stings the eyes. Fortunately, you can use a number of techniques to adapt your earthly eyes to the water. If these techniques do not work for you, then for safe underwater vision in the pool, it is recommended to use goggles or a swimming mask.

Underwater vision in the ocean. Swimming in a natural pool of water will not cause eye irritation from chlorine, but since the water will be free of chlorine, it will contain a variety of bacteria and contaminants. Near the coastline, waves constantly lift sand and small stones from the bottom, which creates the possibility of scratching the cornea of ​​the eye. However, swimming away from shore may be more suitable for taking a look under the water.

Underwater vision in the lake. In a freshwater lake main danger for the eyes represent bacteria. While you won't necessarily get into trouble coming into contact with the single-celled lake creatures, it's wise to wear eye protection (goggles or a swim mask) if you want to get a glimpse of the underwater world. In addition, in shallow areas of the lake, when swimming, you yourself can raise dirt and sand from the bottom, which can damage your unprotected eyes.

Don't forget to remove contact lenses. In any of the above situations, you must first remove your contact lenses. While there is some risk of simply losing the lenses (although the water pressure should keep them in place), the greater danger is the possibility of bacterial infection on the lenses.

• If you wear glasses or contact lenses to improve your vision, you can have a swimming mask made according to the appropriate prescription. With it you will be noticeably safer to swim than to try to see the underwater world with the naked eye. This option is suitable for all those who already do not see very well without glasses.

The use of aids

1. Put on your goggles. Goggles will allow you to see well underwater and prevent eye irritation. The glasses are securely fixed on the head with an elastic band. Putting on glasses is very simple: first, place the lenses on your eyes, and then pull the elastic band from the glasses over your head. The elastic should be pressed firmly against the top of your head, but not too tightly to cause discomfort.

   Use a swimming mask. A swimming mask provides the swimmer with additional protection, as it not only protects the eyes, but also pinches the nose. If you feel uncomfortable with air coming out of your nose underwater, then with a mask you no longer have to hold your nose with your hand! Like glasses, the mask is fixed on the head with a rubber strap (only wider). You should be able to swim underwater without having to press the mask further against your face.

   Consider scuba diving. Scuba diving is diving under water using oxygen cylinders (or cylinders with a special gas mixture) for breathing. Divers equip themselves with masks, wetsuits, fins and buoyancy compensators to navigate as safely as possible underwater and explore the seabed, reefs, caves and shipwrecks. If you're interested in diving, look for training courses near you! There are some nuances to this activity that need to be learned to minimize the risks associated with moving underwater, as humans are not adapted to this environment.

View of the ocean from above and from within

Ride on a glass bottom boat. Such boats are specially designed so that passengers can clearly see the expanses of water under their feet. They are often used on tours to reefs, wrecks and other water attractions. If we compare these tours in cost with other types of exploration of the deep waters, they are relatively affordable. They are organized in many coastal cities and in picturesque water basins.

It’s probably difficult to find something more beautiful than cutting through soft, pliable spaces and admiring the stunning underwater world that normal conditions not available to the human eye. But to do this, you need to learn to swim and do it underwater with fantastic confidence and grace. Some people may have trouble sinking to the bottom. Newbies just float to the surface. There are also those who cannot open their eyes there. And others will not be able to hold their breath for more than ten seconds. How can all these difficulties be overcome?

Theory and practice

Before diving, you need to study the theory of diving and learn how to do it correctly. Usually, classes begin only with an experienced partner. They do it alternately. One person goes down, and the second one insures him at this time. After this, partners change. Diving without oxygen is prohibited. First you need to do deep breath and then slowly dive in. Those beginners who neglect this rule may choke. The brain can simply give a reflex command to inhale involuntarily.

Diving for a long time is very dangerous. It is best to make a plan before starting a dive that will take into account weather conditions. Any swimmer should know what to do if danger arises. Do not use excessively heavy ballast. This may delay the equalization of pressure differences. Before diving, it is better to remove the tube from your mouth.

If pain in the ears appears, stop further diving to avoid rupture eardrums. It is forbidden to quickly release all the air. This may interfere with alignment. You should not look down while diving. Ascent is always done gradually. Between dives take breaks of at least twelve hours. For beginners, shallow water training is required.

How to learn to dive into the depths?

To learn how to dive, you need to go into the pool approximately up to your chest. Any sinking object can be placed at the bottom. The main thing is that this thing is visible under water and easy to get. Now you need to try to get it from the bottom. There is nothing complicated about it. It is better to do this exercise more than once for training.

After this, you should try to dive for the thing upside down. To do this, lie on the surface, make strokes with your hands towards the bottom and forward. The head drops below the level of the legs. At first, some difficulties may arise during training. This is explained by the fact that the liquid tries to push the body back.

It will take some effort to get to the bottom. Every experienced diver knows that it is most practical to swim breaststroke. In addition to the fact that it is easier to make strokes with your hands, your body will swim in the right direction on its own. When the object from the bottom is in your hands, you need to make a stroke in the direction of the surface. This way you can emerge quickly. Now you can complicate the task - you should put the object on the bottom again and move some distance away. You need to dive into the water and try to get to it.

How to learn to hold your breath for a long time?

The first training should be done on land. You need to take a deep breath and try not to breathe for a long time. When you feel like you're running out of air, you need to slowly let it out through your mouth.

If everything is done correctly, then a whistling sound should appear during this. After training on land, you can try to do the same in water.

There is no need to dive at first, just lower your face below the surface. We must remember that exhalation is done gradually. This feature will increase the time spent under water. At the same time, breathing does not stop. You need to try to hold the air not in your mouth, but in your lungs. Otherwise, you won’t be able to dive for more than a few moments.

How to learn to swim quickly underwater?

To learn how to swim underwater, you need to read one simple instruction:

1. The first thing you need to know is that any body movements should be minimal. It is a mistake to believe that if you flounder quickly and a lot, you will be able to swim faster. This way you can either float or go to the bottom.
2. When swimming underwater, it is better to make smooth movements. Your hands should seem to cut through the water. The legs should move relatively slowly.
3. In swimming, body condition plays a big role. For this reason, it is better to relax him.
4. For initial lessons, it is best to visit the pool. Any swimmer feels safe there.
5. Before you can start learning to swim underwater, you need to master the skill of diving. Without this nothing will work.

Secrets of scuba diving

Usually the idea of ​​learning to scuba dive comes to people near the water while on vacation. Some guy with a tank on his back introduces himself as an instructor and offers to master everything in a short time. Self-training at home in any case ends in open water, so a beginner will definitely return to it.

Typically, a full course of such training ranges from 20 to 25 hours. Of course, with self-study, this time increases several times. After training, many questions may arise (what type of equipment is best to buy and where, with whom and when to go diving, how to continue your training). The instructor remains one of the main assistants, and most often the only adviser. For this reason, home workouts may not be effective.

But at the very least you can learn to snorkel. To do this, it is not necessary to take ammunition and scuba gear.

How to snorkel underwater?

Everyone has seen on TV how fearless scuba divers like Jacques-Yves Cousteau dive into the water column, but not everyone knows what difficulties can arise during a dive.

The first difficulty is how to put on a mask?

The mask must be pulled over the head so that it fits tightly enough to the face, otherwise air will penetrate. But you shouldn’t pull the elastic too hard, since the elastic should only support the mask. The main thing that keeps the mask on the face is the vacuum. You just need to press down on the mask and release excess air, then it will stick to your face and won’t go anywhere.

The second difficulty is how to hold the phone?

The tube must be held with your teeth. To start, attach the middle of the tube to the mask so that you have another anchor point besides the jaw. Bite down on the tube and blow out the air.

There should be no water in the tube, otherwise when you inhale it will get into your mouth and lungs. To prevent this from happening, always keep your tongue on the border with the tube so that the passing air first hits the tongue and then goes around it into the lungs. This way you will always feel droplets or streams of water with your tongue and will not swallow water.

Hold your head so that the top of the tube is always exposed to air. If you suddenly get water in your snorkel, spit out the snorkel, float up, pour the water out of it and continue your swim.

The third difficulty is how to prevent the mask from sweating?

The mask fogs up due to the temperature difference between your body and the water. Since the water temperature is lower, condensation accumulates inside, right before your eyes. Some people advise rinsing the inside of the glass with salt water or even spitting on it. None of these methods will work, as it is a myth. If you are annoyed by glass fogging, then do not buy a mask with your nose inside, as steam still comes out of it when you breathe. Buy only with the nose separately and use special anti-fog agents. They are usually enough for 1-3 dives.

The fourth difficulty is what to do if water gets into the mask?

We are all living people and our face moves, and sometimes due to facial movements a little water gets inside. To get rid of it, you need to roll over on your back, turn the glass of the mask horizontally to the ground and blow air into the mask with your nose. Thus, the air will create pressure and squeeze out excess water. It will only work for those whose noses are inside.

The fifth difficulty is how to prevent your ears from getting stuffy?

When diving to a depth of even 2-3 meters, the ears begin to stuff up. You need to release the air from your ears that is creating excess pressure. Pinch your nose with your hand and create air pressure in your nose and ears so that excess bubbles leave you and dive further without pain.

How to swim underwater with your eyes open?

There are several ways to swim and see what's going on around you. Firstly, you can look here with your eyes slightly open. It is necessary to open your eyes slightly, and not widen them. Don't be afraid. It is completely harmless to human health. But you should immediately warn that a chlorinated pool or salty sea will have a detrimental effect on the mucous membrane and irritate it. You may notice itching in the eyes and slight redness after such swimming. And finally, the picture itself is not very clear here, so it’s better to arm yourself with a mask or special glasses. They are selected purely individually in specialized stores.

Games for developing scuba diving

There are a number of games for developing scuba diving. To quickly learn to swim underwater, it is very good to use games, they help to turn off attention to the game itself and at this time the body begins to automatically learn to swim at the level of reflexes. One of them is called “Who can hide faster.” At the instructor’s signal, you need to quickly sit down and dive into the water. Several people participate in the game. Another game is called “little frogs”. The players are located in a circle. At the word "Pike!" The “little frogs” must jump up, and at the command “Duck!” - sit down. If someone makes a mistake, then he stands in the center and continues the game there. There is a game called “find the treasure,” in which players learn to find an object and dive for it.

What mistakes should you not make?

Safety precautions should not be neglected. All equipment, yours and your partner's, must be checked. Blowing away strands of hair that are in your eyes, for example, looks quite cute and erotic. However, it is unlikely that it will be possible to do this under water. It is necessary to immediately remove hair from under the mask to avoid flooding and discomfort due to this.

You should not be immersed in vertical position. The diver's head is a kind of rudder. When in a vertical position, a person usually swims only upward. Another one of common mistakes- the suit is too thin. You need to remember that you have to dive in cold weather. wet liquid, even if this action is performed in tropical latitudes.

In conclusion, it must be said that during the first training a person will probably be shy and may feel insecure. It is not right. The most important thing is to free yourself from complexes and constraint, and follow the goal you set for yourself!

Maybe once upon a time, long ago, we were inhabitants of aquatic environments and came out of the water. There is no point in arguing. The main thing is that now a person exists on land, there is not liquid around, but air, and our vision is adapted to work in air conditions, and not in liquid ones. But interest in water, with all its peculiarities and unusual features, remains. After all, we encounter this substance all the time; it plays an invaluable role in our lives.

This article will help those interested in understanding underwater vision. Everyone understands from childhood that it is somehow not like that. But why? Some know the answer for sure, others don’t even think about it, others intuitively guess, but cannot describe it in words.

Here you will find answers to the questions that interest you, you will understand why water distorts the image of objects, why we see some strange picture in liquid.

You will also learn how fish see and whether all fish see the same, what is the main difference between the structure of the visual organs of fish and humans.

In addition, you will find lengthy discussions by the author on the topic of how our eyes would evolve if we immersed ourselves in living under the surface of the water.

Why do we see everything differently under water than in the air?

Let's start by answering this fundamental question. It would seem that water is a transparent substance, like air. And it should not interfere with getting a good picture. In fact, as most of us know, it interferes, makes the image unusual, unclear, and not as we would like. Why? Let's try to figure it out quickly and simply.

Let us first recall what refraction is. This is when light waves, falling from one medium to another (in our case from air to water) change their direction. It is because of refraction that the picture under water is significantly different from the picture on land.

The fact is that the refractive index of water (the ratio of the speed of light in a vacuum to the speed of light in a given medium) is 1.34, vitreous, the cornea (elements of the human visual organs) has the same indicator - 1.34, and for the lens, the biological lens in our eye - 1.43.

As you can see, there is either no difference between the indicators, or it is minimal. If they were completely identical, then, probably, we would not be able to see anything at all under water.

But there are still minimal differences. They are the ones who influence the fact that the image is not focused on the retina, as happens in people with good eyesight in conditions familiar to humans, but behind the retina, as in far-sighted people.

On the retina itself, the picture is muddy, fuzzy. Water seems to be a dispersing biconvex lens.

Interestingly, people with myopia, which is when the image is formed not on the retina, but in front of it, see several better persons with good eyesight. In this case, it turns out that moisture with its refractive powers, as it were, corrects myopia, allowing the image to focus not in front, but on the retina itself.

And what about the fish?

Here are fish, they spend their entire lives under water. Moisture for them is a familiar environment where they hunt, breed, spend their free time, if they have it. We can say with confidence that they see in the liquid what they need. Surely nature took care of this. But why? What's in their eyes?

We answer. The fact is that in fish the lens has a very convex shape, reminiscent of a ball. Its refractive index is the largest when compared with the lenses of humans and all known animals.

It turns out that the difference between the refractive indices of moisture and the lens increases (the lens has more), as a result of which the image in fish focuses on the retina, they get a fairly clear, high-quality picture.

It should be emphasized that the different fish visual abilities vary. For example, daytime predators are the most vigilant. This is asp, pike, trout. They are able to detect food mainly through their eyes. Fish that eat plankton and benthic organisms see quite well.

But, for example, such freshwater inhabitants as burbot, pike perch, catfish, bream most often go hunting at night. Nature endowed them special structure organs of vision, which allows them to search for their victims at dusk.

In the eyes of night hunters there is a so-called tapetum. This is a special layer of guanine crystals, whose task is to concentrate the light that has passed through the retina and send it back to the retina.

It turns out that the same beam of light is used twice.

The tapetum is not only about fish that hunt in the dark. This element of the visual organ is present in terrestrial nocturnal predators.

And that is not all. Fish can see objects in the water long distances. This happens due to a special muscle (falciform process), which is able to delay the lens.

But in general, fish are short-sighted. Most often, they are able to clearly see the picture at a distance of 1 - 1.5 meters.

The most sharp vision in underwater predators. If the water is clear and calm, they can see objects at a distance of 10 - 12 meters.

We are sure you will be interested to know that some fish are able to illuminate the space around them themselves. It's all about the light energy that they produce. Thanks to this, we can observe an amazing phenomenon - luminous creatures swimming in the darkness of the underwater depths.

It should be noted that fish, like animals, are very, very different. Each species has its own living conditions, its own food, its own interests and habitat. Accordingly, fish also have some differences in the structure of their visual organs, which allows them to live in precisely such conditions.

In general, the role of vision as a source of information in aquatic inhabitants is very significant. This is not only the search and capture of food, but also orientation in space, preservation of the flock, and reproduction...

Factors affecting quality human vision under the water

Everything is clear with refraction. This main reason, which we see rather poorly when underwater. But she's not the only one. Even if we assume that the refractive index of moisture is different, we still would not get the same picture as in air.

Why? Let's think together.

First. Water is not the natural habitat of the human visual organs.

Remember, for example, how you dive in a river and open your eyes. You're not very comfortable, are you?

Of course, you can get used to everything. But it is a fact that those who like to swim underwater with their eyes open often emerge with reddened eyes. Human eyes lack some kind of protective mechanism that would protect the mirrors of the soul from discomfort.

Second. Water composition.

Even ideal life-giving moisture would not be suitable as a comfortable environment for our visual organs. But nothing is ideal!

We encounter, for example, river water. First of all, it is not very transparent. And that's putting it mildly. Secondly, it is full of impurities that can further irritate the mucous membrane of the eyes. The result is an even fuzzier, blurry picture.

Or the life-giving moisture of the sea. Some argue that it is somewhat more comfortable for human eyes compared to fresh liquid, because it contains a certain amount of salts, and their concentration is similar to the concentration of salts in our bodies. This is partly true.

The fact is that in different bodies of water the concentration is different. For example, the most salts are in Red and Dead Seas. And least of all about the inland seas, such as the Baltic and Black.

It turns out that the closer the level of salt concentration in water is to the same level in humans, the more comfortable we will feel when opening our eyes under water. The winners here are the Black and Baltic Seas. You can safely swim and dive in them without fear of irritation of the mucous membranes.

Things are completely different in saltier bodies of water. There, a person runs the risk of getting quite serious irritation of the mucous membranes. Even the skin, if it is too delicate, can suffer from the effects of salts.

In any case, you should approach swimming with your eyes open sea ​​conditions carefully. It is recommended to get used to it gradually.

By the way, there are also bodies of water that look safe, but swimming in them with open, unprotected eyes is not advisable. These are healing mineral pools with increased content hydrogen sulfide. This component irritates the mucous membranes, as evidenced by a fairly strong pain.

But we went very far, to rivers and other bodies of water. Meanwhile, you can immerse yourself in the life-giving moisture and open your eyes in it right at home, in the bathroom. This is what most children do during the required bath, which we have no doubt about.

Here, completely different impurities can negatively affect the organs of vision, and the main one is chlorine. It is this substance, which is, in fact, poison, that negatively affects the mucous membrane, causing quite serious redness and irritation. It is clear that in this state the eyes are unlikely to be able to get nice picture while underwater.

How can you improve your vision under water?

So, we have already discussed why our picture is unclear underwater, and also what can make it even worse. Now we need to focus on the following: how can we improve the quality of the resulting image? How, when immersed, can you see the maximum of everything?

The answer to this question is quite simple. We need some kind of transparent partition between the eyes and the liquid. And such a partition becomes underwater goggles and underwater masks. People actively swim in them, orient themselves in space, and see far enough and with high quality. Now all that remains is to find out why this happens.

Remember, we wrote that water does not have the same refractive index as air. And that’s why our picture during diving is bad. Everything changes when a layer of air appears between the water and the eye, i.e. familiar environment. Underwater masks and goggles provide just that, making the underwater world clear and attractive to humans.

Of course, additional devices will not solve the problem of turbidity of life-giving moisture, which can significantly limit the view. It is clear that snorkeling in the river and in the sea are two different things. But still…

Miracles of refraction

In an article about vision under water, we cannot fail to mention the wonders of refraction, how objects that are in water change.

It turns out that most children in certain period life are puzzled by the question (approximately): why are the sizes of the same ball on land and in a container with water different? There are similar questions about why a body immersed in a full bath becomes large. Or why a pencil that is not completely lowered into a glass of water appears to be broken.

All these are miracles of refraction, which are not miracles at all, but the result of physical laws. Here, for example, is the increase in objects.

Yes, indeed, it is so. If we take, for example, a children's cube and, having previously measured it with a ruler, lower it into a glass vase with thin walls, we will observe the following. When measured, the side of the cube will become approximately 33% larger (plus the walls of the vessel will play a small magnifying role).

Clearly, the point is not that the cube is saturated with moisture and swells. The refraction of light is to blame. It makes our legs look strange when we lie in the bathtub. It makes objects underwater appear closer than they actually are, by about 25%.

In general, moisture, as we have already written, is a kind of lens, therefore the image is obtained approximately like after a biconvex lens.

What if…

Many people are interested in how a person’s organs of vision would change, how they would evolve, if he were forced to live in the depths of water. Let's try to think about the answer to this question together.

Firstly, the lifestyle that a person would lead is important.

If he swam closer to the surface, it would be one thing, but at depth, where there is much less light, it would be another. Therefore, a tapetum would probably appear in the structure of the organ of vision, i.e. a layer of crystals that collect light.

Secondly, the human eye is now quite sensitive in water, the liquid can cause irritation and redness.

Therefore, if you change your habitat to aquatic, you need to acquire special protective films that would limit the impact of moisture on the elements of the visual organs.

Thirdly, the issue of light refraction.

Even if liquid is not a medium where you can, in principle, see as well as on land. But some fish can see at 10 - 12 meters. And all thanks, among other things, to the convex lens. It would not hurt for a person like him to have the image focus not behind the retina, but on it, and be accurate and of high quality.

Fourthly, coverage of the territory.

It wouldn't hurt to enlarge it either. Yes, a person’s head is actively moving, but will this be enough in underwater world? Is not a fact. Therefore, it is quite likely that the organs of vision will increase somewhat and move out of their orbits somewhat, will rotate more actively and will be able to capture large quantity information. It is also possible that the location of the eyes will change - they will move somewhat to the sides.

So far, life-giving moisture for a person is only a temporary environment in which he feels relatively comfortable. It takes many, many years of evolution for us, our visual organs, to be able to live as comfortably in water as on land.