Antipyretics for children are prescribed by a pediatrician. But there are emergency situations for fever when the child needs to be given medicine immediately. Then the parents take responsibility and use antipyretic drugs. What is allowed to give to infants? How can you bring down the temperature in older children? What medicines are the safest?
With the advent of computers and television, people's eyesight began to deteriorate. Those who saw well in childhood now wear glasses or contacts. So what should vision be like, what is considered normal?
At their core, people are quite careless. Until they have any symptoms of disease, they do not think about their health. And some, even in this case, will endure until the last moment, until something begins to hurt so much that they have no strength.
The same is true with vision: until a person realizes that the image has become blurred, he will not take any measures. So what kind of vision should there be and what is considered normal?
Children's vision
To recognize the world around us, we need not only to have vision itself, but also its acuity. It helps us to notice various details. If a person can see very small details, he has good visual acuity.
It has long been known that the acuity of central vision varies in different periods. life cycle. For example, in newborns it is very low and becomes normal only by the age of 5. In some situations, you will have to wait up to 15 years.
Adult vision
Most often, adults have poor eyesight. And the closer the old age, the more the situation worsens. The decrease in central and peripheral vision with age is a natural process, because the eyes, like other organs of the human body, are subject to aging.
What kind of vision should be, only an ophthalmologist knows best. But it is not necessary to go to his appointment to check whether you need glasses or not. You can do trial testing at home. It is enough just to find a large table of an ophthalmologist.
6/6 is an indicator of normal visual acuity. The first number indicates the distance from which the test is carried out (6 meters). The second number is the distance from which normally seeing people can read the same line on the table. If the second number is less than the first number, the vision is better than normal; if it is more, then it is worse than normal.
- There are professions where good vision- required condition. You cannot become a pilot, jeweler, athlete, driver if you have a big disadvantage. Either contact lenses or glasses will help here (although it will be problematic to play football in them).
- To obtain a driving license, you also need to have good vision. For category "B" - 0.6 units for the eye that sees better, and 0.2 for the one that sees worse.
- The average person does not know what vision should be to play sports. If you have difficulty seeing, you should consult a doctor before starting training. If you have problems with the retina, you should never play sports. Heavy strain can cause retinal tears and detachment, which can result in vision loss.
Our vision makes our life richer, more informative, more active. Therefore, it is so important for a person to promptly solve all problems that arise with the eyes, because even the slightest possibility of stopping seeing this beautiful world is frightening.
The eyes are a window to the world, they are a reflection of the state of our soul, they are a repository of riddles and secrets.
In this article we will pay special attention to central and peripheral vision.
What are their differences? How is their quality determined? What are the differences between peripheral and central vision in humans and animals, and how do animals see in general? And how to improve peripheral vision...
This and much, much more will be discussed in this article.
Central and peripheral vision. Interesting information.
First about central vision.
This is the most important element of human visual function.
It received this name because... provided by the central portion of the retina and the central fovea. Gives a person the opportunity to distinguish shapes and small details of objects, therefore its second name is shaped vision.
Even if it decreases slightly, a person will immediately feel it.
The main characteristic of central vision is visual acuity.
Her research is of great importance in assessing the entire human visual apparatus, for tracking various pathological processes in the organs of vision.
Visual acuity refers to the ability of the human eye to distinguish between two points in space located close to each other, at a certain distance from the person.
Let us also pay attention to such a concept as the visual angle, which is the angle formed between the two extreme points of the object in question and the nodal point of the eye.
It turns out that the larger the visual angle, the lower its acuity.
Now about peripheral vision.
It provides a person’s orientation in space and makes it possible to see in darkness and semi-darkness.
How to understand what is central and what is peripheral vision?
Turn your head to the right, catch an object with your eyes, for example, a picture on the wall, and fix your gaze on any individual element of it. You see him well, clearly, don’t you?
This is thanks to central vision. But besides this object, which you see so well, a large number of different things also come into your field of vision. This is, for example, a door to another room, a closet that stands next to the painting you have chosen, a dog sitting on the floor a little further away. You see all these objects unclearly, but, nevertheless, you see, you have the ability to capture their movement and react to it.
This is peripheral vision.
Both human eyes, without moving, are capable of covering 180 degrees along the horizontal meridian and a little less - about 130 degrees along the vertical.
As we have already noticed, the acuity of peripheral vision is less than central. This is explained by the fact that the number of cones, from the center to peripheral departments retina is significantly reduced.
Peripheral vision is characterized by the so-called visual field.
This is the space that is perceived by a fixed gaze.
Peripheral vision is invaluable to humans.
It is thanks to it that free, habitual movement in the space surrounding a person and orientation in the environment around us is possible.
If peripheral vision is lost for some reason, then even with full preservation of central vision, the individual cannot move independently, he will bump into every object on his way, and the ability to see large objects with his gaze will be lost.
What kind of vision is considered good?
Now consider the following questions: how the quality of central and peripheral vision is measured, as well as what indicators are considered normal.
First, about central vision.
We are accustomed to the fact that if a person sees well, they say about him “one in both eyes.”
What does it mean? That each eye individually can distinguish two closely spaced points in space, which give an image on the retina at an angle of one minute. So it turns out a unit for both eyes.
By the way, this is just the bottom line. There are people who have vision 1,2, 2 or more.
We most often use the Golovin-Sivtsev table to determine visual acuity, the same one with the well-known letters Ш B in the upper part. A person sits in front of the table at a distance of 5 meters and closes alternately his right and left eyes. The doctor points to the letters in the table, and the patient says them aloud.
The vision of a person who can see the tenth line with one eye is considered normal.
Peripheral vision.
It is characterized by the field of view. Its change is an early and sometimes the only sign of some eye ailments.
The dynamics of changes in the visual field makes it possible to assess the course of the disease, as well as the effectiveness of its treatment. In addition, through the study of this parameter, atypical processes in the brain are revealed.
Studying the visual field is determining its boundaries, identifying defects in visual function within them.
To achieve these goals, we use various methods.
The simplest of them is the control one.
Allows you to quickly, literally in a few minutes, without using any instruments, determine a person’s field of vision.
The essence of this method is to compare the physician’s peripheral vision (which should be normal) with the patient’s peripheral vision.
It looks like this. The doctor and the patient sit opposite each other at a distance of one meter, each of them closes one eye (opposite eyes close), and open eyes act as a fixation point. Then the doctor begins to slowly move his hand, which is located on the side, out of the field of view, and gradually bring it closer to the center of the field of view. The patient must indicate the moment when he sees her. The study is repeated from all sides.
Using this method, a person's peripheral vision is only roughly assessed.
There are also more complex methods that give deeper results, such as campimetry and perimetry. 
The boundaries of the visual field may vary from person to person and depend, among other things, on the level of intelligence and the structural features of the patient’s face.
Normal indicators for white color are as follows: top - 50o, outward - 90o, top to outside - 70o, top to inside - 60o, bottom to outside - 90o, bottom - 60o, bottom to inside - 50o, inside - 50o.
Color perception in central and peripheral vision.
It has been experimentally established that human eyes can distinguish up to 150,000 shades and color tones.
This ability has an impact on various aspects of a person’s life.
Color vision enriches the picture of the world, gives the individual more useful information, and influences his psychophysical state.
Colors are actively used everywhere - in painting, industry, scientific research...
The so-called cones, light-sensitive cells that are found in the human eye, are responsible for color vision. But the rods are responsible for night vision. There are three types of cones in the retina, each of which is most sensitive to the blue, green and red parts of the spectrum.
Of course, the picture we get thanks to central vision is better saturated with colors compared to the result of peripheral vision. Peripheral vision is better at picking up brighter colors, such as red or black.
Women and men, it turns out, see differently!
Interestingly, women and men see things somewhat differently.
Due to certain differences in the structure of the eyes, representatives of the fair sex are able to distinguish more colors and shades than the strong part of humanity.
In addition, scientists have proven that men have better developed central vision, while women have better peripheral vision.
This is explained by the nature of the activities of people of different sexes in ancient times.
Men went hunting, where it was important to clearly concentrate on one object and not see anything else. And the women looked after the housing and had to quickly notice the slightest changes, disturbances in the usual flow of everyday life (for example, quickly notice a snake crawling into a cave).
There is statistical evidence to support this statement. For example, in 1997, in the UK, 4,132 children were injured in road accidents, of which 60% were boys and 40% were girls.
Besides, Insurance companies note that women are much less likely than men to get into car accidents that involve side impacts at intersections. But parallel parking is more difficult for beautiful ladies.
Women also see better in the dark and notice more small details in a wide field compared to men.
At the same time, the eyes of the latter are well adapted to tracking an object at a long distance.
If we take into account other physiological features women and men, the following advice will be formed - during a long trip it is best to alternate as follows - give the woman the day, and the man the night.
And a few more interesting facts.
In beautiful ladies, the eyes get tired more slowly than in men.
In addition, women's eyes are better suited for observing objects at close range, so they can, for example, thread a needle much faster and more dexterously than men.
People, animals and their vision.
Since childhood, people have been fascinated by the question - how do animals, our beloved cats and dogs, birds soaring in the heights, creatures swimming in the sea see?
Scientists have been studying the structure of the eyes of birds, animals and fish for a long time so that we can finally find out the answers that interest us.
Let's start with our favorite pets - dogs and cats.
The way they see the world is significantly different from how a person sees the world. This happens for several reasons.
First.
Visual acuity in these animals is much lower than in humans. A dog, for example, has a vision of about 0.3, and cats generally 0.1. At the same time, these animals have an incredibly wide field of vision, much wider than that of humans.
The conclusion can be drawn as follows: the eyes of animals are maximally adapted for panoramic vision.
This is due to both the structure of the retina and the anatomical location of the organs.
Second.
Animals are much better than a man see in the dark.
It is also interesting that dogs and cats see even better at night than during the day. All thanks to the special structure of the retina and the presence of a special reflective layer.
Third.
Our pets, unlike humans, distinguish moving objects better than static objects.
Moreover, animals have a unique ability to determine the distance at which an object is located.
Quadruple.
There are differences in the perception of colors. And this despite the fact that the structure of the cornea and lens in animals and humans is practically no different.
Humans can distinguish many more colors than dogs and cats.
And this is due to the structural features of the eyes. For example, a dog’s eyes have fewer “cones” responsible for color perception than a human’s. Therefore, they distinguish less colors.
Previously, there was a general theory that the vision of animals, cats and dogs, is black and white.
This is if we talk about the differences between human vision and pets.
Now about other animals and birds.
Monkeys, for example, see three times better than humans.
Eagles, vultures, and falcons have extraordinary visual acuity. The latter can clearly see a target up to 10 cm in size at a distance of about 1.5 km. And the vulture is able to distinguish small rodents that are located 5 km away from it.
The record holder in panoramic vision is the woodcock. It's almost circular!
But the pigeon we are all familiar with has a viewing angle of approximately 340 degrees.
Deep-sea fish see well in absolute darkness, seahorses and chameleons can generally look in different directions at the same time, and all because their eyes move independently of each other.
Here are some interesting facts.
How does our vision change throughout our lives?
How does our vision, both central and peripheral, change during life? What kind of vision are we born with, and what kind of vision do we come to old age with? Let's pay attention to these issues.
At different periods of life, people have different visual acuity.
A person is born into the world, and his blood pressure will be low. At the age of four months, the child’s visual acuity is approximately 0.06, by the year it grows to 0.1-0.3, and only by the age of five (in some cases it takes up to 15 years) vision becomes normal.
Over time, the situation changes. This is due to the fact that the eyes, like any other organs, undergo certain age-related changes; their activity gradually decreases.
This means that the older a person gets, the more light he needs for reading and other activities. In addition, in old age, changes in lighting brightness are very painful. The world around an elderly person seems to fade and become dull.
It is believed that deterioration of visual acuity is an inevitable or almost inevitable phenomenon in old age.
Let us highlight the following points.
*
With age, the size of the pupils decreases due to weakening of the muscles that are responsible for their regulation. As a result, the reaction of the pupils to the light flux worsens.
*
Also, with age, the eyes recognize colors worse, the contrast and brightness of the image decreases. This is a consequence of a decrease in the number of retinal cells that are responsible for the perception of colors, shades, contrast and brightness.
What happens to peripheral vision?
It also gets worse with age - lateral vision worsens, visual fields narrow.
This is very important to know and take into account, especially for people who continue to lead an active lifestyle, drive a car, etc.
A significant deterioration in peripheral vision occurs after 65 years.
The following conclusion can be drawn.
A decrease in central and peripheral vision with age is normal, because the eyes, like any other organ of the human body, are susceptible to aging.
I can't be with poor eyesight...
Many of us have known since childhood what we want to be in adulthood.
Some dreamed of becoming a pilot, some a car mechanic, some a photographer.
Everyone would like to do exactly what they like in life – no more, no less. And what a surprise and disappointment it can be when, upon receiving a medical certificate for admission to one or another educational institution, it turns out that the long-awaited profession will not become yours, and all because of poor eyesight.
Some people don’t even think that it can become a real obstacle to the implementation of plans for the future.
So, let's figure out which professions require good vision.
It turns out there are not so few of them.
For example, visual acuity is necessary for jewelers, watchmakers, people involved in precision small instrument making in the electrical and radio engineering industries, in optical-mechanical production, as well as those who have a typographic profession (this could be a typesetter, proofreader, etc.).
Undoubtedly, the vision of a photographer, seamstress, or shoemaker must be sharp.
In all of the above cases, the quality of central vision is more important, but there are professions where peripheral vision also plays a role.
For example, an aircraft pilot. No one will argue that his peripheral vision should be as good as his central vision.
The profession of a driver is similar. Well-developed peripheral vision will allow you to avoid many dangerous and unpleasant situations, including emergency situations on the road.
In addition, auto mechanics must have excellent vision (both central and peripheral). This is one of the important requirements for candidates when hiring for this position.
Don't forget about the athletes either. For example, football players, hockey players, and handball players have peripheral vision that approaches ideal.
There are also professions where it is very important to correctly distinguish colors (preservation of color vision).
These are, for example, designers, seamstresses, shoemakers, and workers in the radio engineering industry.
We train peripheral vision. A couple of exercises.
Surely you have heard about speed reading courses.
The organizers undertake to teach you, in a couple of months and for not such a large amount of money, to swallow books one by one, and remember their content perfectly. So, the lion’s share of time in the courses is devoted to the development of peripheral vision. Subsequently, a person will not need to move his eyes along the lines of a book; he will immediately be able to see the entire page.
Therefore, if you set yourself the goal of developing excellent peripheral vision in a short time, you can enroll in speed reading courses, and in the near future you will notice significant changes and improvements.
But not everyone wants to spend time on such events.
For those who want to improve their peripheral vision at home, in a calm environment, here are a few exercises.
Exercise number 1.
Stand near the window and fix your eyes on any object on the street. This could be a satellite dish on a neighboring house, someone's balcony, or a slide on the playground.
Recorded? Now, without moving your eyes and head, name the objects that are near your chosen object.
Exercise number 2.
Open the book you are currently reading.
Choose a word on one of the pages and fix your gaze on it. Now, without moving your pupils, try to read the words around the one on which you fixed your gaze.
Exercise number 3.
For this you will need a newspaper.
In it you need to find the narrowest column, and then take a red pen and draw a straight thin line in the center of the column, from top to bottom. Now, glancing only along the red line, without turning your pupils to the right and left, try to read the contents of the column.
Don't worry if you can't do it the first time.
When you are successful with a narrow column, choose a wider one, etc.
Soon you will be able to look at entire pages of books and magazines.
Before we dive into what it means to have vision plus, let's first understand how the visual system functions.
First, the light ray is refracted by the cornea so that it is directed at the main lens of the eye - the lens. It looks like a transparent biconvex body, covered in an elastic shell. This membrane is attached to special muscles of the ciliary body. Due to their contraction, the lens capsule is tensioned or weakened, and it changes its shape from almost flat to spherical. Such changes are necessary to create a refractive lens of different shapes, depending on the distance to the object in question. A ray of light passing through the lens is focused on the retina. Changing the curvature of the lens allows you to achieve better focus and clarity of vision.
When looking into the distance, the ciliary muscles relax and the lens takes on a flatter shape. When it is necessary to view an object close up, the curvature of the lens increases to its maximum, it becomes like a ball.
Violations of this mechanism lead to conditions called refractive errors and are expressed in myopia, farsightedness or astigmatism.
Signs
In a farsighted eye, the refraction of rays in the lens is too weak, and the focus forms behind the surface of the retina. Therefore, a person sees well in the distance, but cannot distinguish objects near. Such a violation is indicated by a “plus” sign. The problem lies in the inability of the muscles to tense and change the curvature of the lens.
Focus in a normal eye (A.) and with positive vision (B. hyperopia)
With myopia (myopia), the ciliary muscles, in a state of spasm or for other reasons, hold the lens in the most tense state, when its optical power is greatest. A person sees objects in the foreground well because the spherical lens focuses the image in front of the retina, but sees poorly in the distance. Ophthalmologists denote myopia with a minus sign.
Digital values
Since the lens is a lens, its optical power can be measured. To designate it, a unit of measurement is used, such as diopters; in a glasses prescription it is designated by the letter D or Dpt. Vision is considered ideal when the eye is able to distinguish two points at a focusing angle of 1.6 degrees, in which case we speak of 100% vision. In practice, this means that when testing vision using a special table (Sivtsev), a person with normal vision must distinguish the letters of the tenth line, which corresponds to the designation V = 1.0, from a five-meter distance.
To check the eyesight of children, they use the Orlova table, where instead of letters, various pictures of the corresponding size are drawn. Also, to the left of the lines, it is indicated from what distance the letters can be seen in it with normal vision. The last, twelfth, line is available to people with 100% vision from a distance of 2.5 m. With other indicators, you can find out about the presence of a refractive error.
To determine the farsightedness index, a special table and a set of lenses of various strengths are used.
The indicator for the far-sighted eye is set by inviting the test person to look at the table through a collecting lens. Such optics allow you to compensate for visual acuity. The optical power of a corrective lens, at which a person will see the tenth line from a distance of 5 meters, and the eleventh is no longer there, and will be in the prescription for glasses. So vision plus one is considered another level of normal, at which correction is not required. Next, depending on the optical power of the lens required for correction, the following degrees of hyperopia are determined:
- first – up to plus 2;
- average – vision from plus 3 to plus 5;
- high – over plus 5.
Age features
Plus vision (farsightedness) is physiological for a newborn. Due to the child's small size eyeball and the great elasticity of the lens capsule in the first months, near vision is blurred, visual acuity is about plus three or even more. As the organs of vision develop, their ability to focus also changes, and visual acuity becomes normal in adults.
If, upon examination by a pediatric ophthalmologist, the prerequisites for maintaining positive vision are determined, then farsightedness correction is performed with glasses. Glasses for children with farsightedness are designed to be worn constantly. Their optical power is selected one unit less than the power of hypermetropia. This technique is justified for children's eyes as it stimulates their growth and helps reduce farsightedness.
Since the structures of the lens and ciliary muscles in children are very elastic and are able to compensate for a refractive error, a vision test is carried out by first instilling eye drops Pilocarpine. This medicine “turns off” the accommodative apparatus of the eye and allows you to identify true or false farsightedness.
Also, due to a genetic predisposition or other factors, a child may develop a refractive error when one eye has a plus indicator, the other minus. This condition requires mandatory correction immediately upon detection, since over time, signals from the weaker eye begin to be ignored by the brain, since they are not informative. Gradually, the eye loses its function and amblyopia develops - a decrease in vision that cannot be corrected.
Also, the optical power of the eye can “change sign” with age. In the second half of life, those who suffer from nearsightedness may notice improved distance vision, but blurred foreground.
Most people after 40–50 years develop so-called senile farsightedness – presbyopia.
The muscles responsible for contracting the lens weaken, and it almost always remains in its flatter form. The so-called “long arm” state develops - a person, in order to see small details or text, moves them further away from himself.
How to eliminate hyperopia
Optics
Vision correction is carried out taking into account the degree of positive vision and concomitant pathologies. If vision is plus 1 dpt, then in most cases corrective optics are not prescribed. When this value approaches 1.5 Dpt, the ophthalmologist may suggest glasses or contact lenses for correction. Lenses must be collective. For older patients, if myopia or astigmatism has previously been diagnosed, two pairs of glasses will be needed - one for distance and one for reading. To avoid confusion, today's glasses can be custom-made with multiple optical zones. They are called bifocal or multifocal, as they include optical areas with different degrees of refraction.
“Plus” vision is corrected with collective lenses
Young people may be prescribed contact lenses for greater comfort. This optical system is installed directly on the eye and has a number of advantages for the user. Firstly, there is no image distortion or glare, as in glasses; secondly, the power of a contact lens may be less than a spectacle lens due to the lack of distance to the cornea; thirdly, a more aesthetic appearance, no fogging, ease of use when playing sports or in the pool.
The lenses are convenient because they can be selected according to your wearing schedule: you can wear the optics all day (12 hours) and take them off at night, or you can choose weekly or even monthly lenses that do not require removal from the eyes during this period.
Contact lenses can also have multiple areas of varying optical power, allowing them to be used for both reading and distance vision at the same time.
Bifocals with reading area (A) and distance (B)
Previously, the material of contact lenses did not allow them to be made powerful enough for high degrees of farsightedness, and if the “plus” was large, then it was necessary to use glasses. New materials make it possible to produce contact lenses with an optical power of +6 Dpt. It should be remembered that lenses should not compensate for vision by 100%. This approach makes it possible to maintain the tone of the ciliary muscles of the eye and maintain their participation in the accommodation process.
As an option for correcting positive vision, you can choose implantable contact lenses. They will need to be installed directly into the eye in front of the iris or in front of the lens. The lens is very elastic, which allows it to be inserted through a very small incision into the anterior or posterior chamber of the eye, where it unfolds independently.
This correction method is used for high levels of “plus” vision, for which laser correction is contraindicated, or the patient has a very thin cornea or defects in the form of keratoconus. Implantable lenses provide the same effect as vision correction with regular glasses or soft contact lenses, but are more convenient in everyday life.
With the help of various optics, you can achieve an instant improvement in vision.
Laser correction of farsightedness
This method of improving vision is suitable for patients aged 18 to 45 years and with visual acuity up to plus 5. The impact in this case is applied not to the lens, but to the cornea - another refractive structure of the eye. The laser “burns” a certain thickness of the cornea in certain places. This will give her a new geometry and lets you change the focus.
The procedure itself lasts about a quarter of an hour and recovery after it is also short. Already after two hours the patient can see the world differently. To further maintain the effect of the operation, the doctor usually prescribes anti-inflammatory (Diftal, Diclofenac) and moisturizing eye drops (Dexpanthenol, Korneregel), complex vitamin preparations with lutein and trace elements for oral administration (for example, Taxofit).
Scheme of laser correction of the cornea profile in hyperopia
Lens replacement
With very high levels of positive vision (up to +20 Dpt), especially in older people, it would be most rational to resort to surgery to replace the lens with an artificial lens - lensectomy. The natural lens is destroyed and extracted, and a lens is placed in its place in the capsule. It can have a special shape that allows you to focus images from different distances. Simpler options have one focus, so the patient will need reading glasses, but vision is restored to 100%.
The decision on the advisability of such radical intervention must be made by the doctor. The patient should know that lens replacement is carried out quite quickly and under local anesthesia, does not require a long stay in the clinic. In terms of its effectiveness, it ranks first among methods of treating farsightedness in older people.
As you can see, “plus” is not always a positive indicator. In terms of vision, it requires correction, which should be entrusted to an ophthalmologist.
The human eye is an entire optical system, quite complex in its design. It contains biological lenses that have their own separate and unique focus. This is how, when light is refracted, a picture is projected. And if the system is working properly, the image will be clear. The focal length has its own value; it is constant and depends on how curved the biological lenses are. IN healthy eyes the average distance should not exceed 24 mm - this is the norm, which is equal to the distance between the cornea and the retina.
When light is refracted, a process called refraction occurs, which has its own measurement values - diopters. If refraction occurs without any deviation, the image falls directly on the retina and is focused there. The definition of normal vision is usually considered to be one or 100%, but this value is relative depending on the individual case.
What is the norm
It has been established that visual acuity is considered to be the norm - 100% or V = 1.0, the refraction of the eye is 0, the normal IOP is 22-24 mm Hg.
The norm is considered to be a combination of indicators of refraction and acuity; pressure in this case refers to third-party assessment factors, but in some cases plays a significant role, because primarily affects the clarity of vision.
Why acuity and refraction are key:
Visual acuity is determined using tables, while refraction is measured linearly, that is, in fact, the length of the position of the focal point is measured in centimeters/meters. If vision abnormalities are detected, the strength of the curvature of the cornea, the degree of image distortion are determined, and one or a combination of the diseases listed below are diagnosed. 
What are the deviations?
Due to the fact that light fluxes are refracted incorrectly, that is, refraction is disrupted, various deviations in vision occur. Most often, people begin to feel blurry objects. Depending on the type of distortion, patients experience the following visual impairments:
- Myopia. Perhaps the most common of the diseases, in which focusing occurs not on the retina, but in front of it. Symptoms: decreased vision of distant objects, fairly rapid eye fatigue, discomfort in the form of pain, pain in the temporal parts of the head.
- Farsightedness. In this case, the focus of the image is behind the retina. A person sees poorly at a distance close to the eyes. Fogging occurs, there is a clear violation of accommodation on the face, and strabismus may occur.
- Astigmatism. Here there is an inability to focus on the retina. The basis of the disorder is the irregular shape of the cornea or lens. The main symptoms: distortion of the image, doubling of objects, fatigue after a short period of time (asthenopia), persistent tension and, as a result, headaches.
- Glaucoma. A complex of diseases based on deviations from normal intraocular pressure. Increased IOP is diagnosed more often than decreased IOP, and has different consequences. When it is low, optic nerve atrophy develops; when it is low, retinal dystrophy develops. With severe damage to the optic nerve, severe deterioration of vision occurs, up to complete blindness. This disease can only be treated surgically and there are several different forms, some of which are irreversible.
- Cataract. Lens opacification disease with progressive effects. The disease can occur at a young age, but mainly develops in the elderly. A person begins to react painfully to light, poorly distinguish color shades, difficulties arise when reading, and vision decreases significantly in twilight and darkness.
Some diseases occur throughout life. This is due to factors such as the specifics of the work, daily eye strain, hazardous production or improper working conditions. Often such diseases can be inherited and already in early age Children may be diagnosed with eye diseases.
Preventive methods
These methods include:
Exercises
Among the most common and simple exercises, there are several. They will help strengthen the muscle groups of the eyes, and therefore stimulate the strengthening of the position of the cornea and lens, blood circulation and the enrichment of all parts of the eye with oxygen.
According to Bates
A famous ophthalmologist of the 19th century, who stated that visual deviations depend on overexertion of groups oculomotor muscles, W. Bates invented a unique method of relaxing the eyes - palming. Nothing is required to use it. Except your own palms. Rub them to create heat and apply them to the eyeballs, pressing lightly with the back of them. Repeat several times. Mentally imagine a beautiful landscape or picture, remember pleasant things, and continue until you feel relaxation in the eye muscles. An indicator will be the fact that the flashes will begin to disappear with your eyes closed.
William Bates Method
According to Norbekov
Norbekov’s eye gymnastics is based on the psychological impact on the body of one’s own consciousness. That is, a positive attitude, faith in success, regular training and gymnastics, a constant smile and good vision “in your pocket.” In fact, everything is not as simple as it seems and delving into Norbekov’s method will require considerable effort and patience, and most importantly the appropriate attitude, so skeptics should better refrain from this method. 
Along with these famous authors, there are several more methods, but they all overlap with each other and have common ground. Without regular use of gymnastics in practice, you can’t expect results, as everyone who uses unconventional methods in practice says.
The famous author Zhdanov suggests doing palming while lying on the bed, this way, in his opinion, there is greater relaxation of all muscles. Covering your eyes with warm palms, you should lie until the spots in front of your eyes completely disappear.
To treat vision, you can use special eye yoga or other eastern methods. However, this requires special training and supervision by an instructor. Using complex health systems without proper knowledge may be useless or harmful to health.
Video
conclusions
Normal vision is a set of indicators of acuity and refraction, which are responsible for the clarity and range of image display. With significant deviations, diseases such as myopia, farsightedness, and astigmatism are observed. For preventive purposes, it is necessary to regularly check acuity using vision tables, and to maintain or slightly restore visual function, methods and sets of exercises have been developed that have a scientific basis.
What is the normal eye pressure for a healthy person? Consider all cases and ages
Intraocular pressure (IOP) is an important diagnostic indicator that allows you to indirectly determine the presence of various ophthalmological diseases.
With the development of various pathological processes, this indicator may increase or decrease, deviating from the established average statistical norm.
Below we will analyze in detail what normal eye pressure should be. healthy person at different ages.
You can read more about the symptoms and causes of this disease here.
What is eye pressure?
Intraocular pressure refers to the amount of tone that occurs between the membrane of the eyeball and its internal contents.
Also, fluid can accumulate in the organs of vision, which leads to an increase in the indicator, and this can lead to such an additional problem as deformation of the vessels through which the fluid is transported.
There are three types of such violations:
- In case of transient disorders, destabilization of IOP is short-term, and it is restored without the need for treatment within a short period.
- With labile disorders, short-term pressure surges are also observed, which go away on their own, but the processes are regular.
- If the excess of the norm is constant and does not go away, they speak of a stable type of pathology.
Such jumps can be dangerous, especially if there is a decrease in IOP.
In such rare cases, which may be caused by trauma, infectious and endocrine diseases, dry eye syndrome may appear.
If the indicator increases, which is diagnosed more often, in the absence of treatment, compression of the optic nerve may occur, which subsequently is fraught with its atrophy.
Changes in pressure in the organs of vision require immediate intervention by specialists and timely treatment.
Normal eye pressure in adults and everything you need to know about it
Intraocular pressure (or ocular tone) is measured in millimeters of mercury.
During the day, such values may change, but if they do not go beyond the designated limits, there is no reason to consult a doctor.
How is IOP measured?
There are several ways to take measurements.
The first of them, named after Professor Maklakov, has been used by ophthalmologists for over a century.
During this procedure, a special medical weight is placed on the cornea of the eye, previously treated with an anesthetic.
For details about all methods of measuring IOP, read a separate article: how to measure intraocular pressure.
It leaves a small dent or imprint on the shell of the eye, which the ophthalmologist subsequently deciphers.
The second method is pneumotonometry, in which pressure is exerted not by a load, but under the influence of a jet of compressed air. Unlike the Maklakov method, this is a less accurate method.
Modern experts prefer more accurate modern diagnostics using an electron diffraction scanner, in which a non-contact measurement occurs.
During this procedure, the production of intraocular fluid is artificially stimulated, after which its outflow is also artificially accelerated.
This method allows you to quickly establish the most accurate results and determine the presence of pathological disorders.
Norms of eye pressure for different ages and in different cases
In most cases, in adults, the norm of intraocular pressure remains unchanged for people of any age, and this indicator can mainly change with some ophthalmological diseases.
40 years
The average value for people aged 40 years and older is considered to be from 10 to 23 millimeters of mercury.
With such indicators, all metabolic and tear-forming processes proceed in a normal natural mode.
This indicator of fundus pressure is the same for men, women and children, although in a child the indicator rarely approaches 20 units.
50-60 years
At the age of 50-60 years, intraocular pressure increases slightly, but this is normal, and an indicator of 23-25 units is not considered pathological and does not require intervention, although this is already a signal that a person may develop glaucoma and others inflammatory processes Therefore, after fifty years of age, it is necessary to undergo an ophthalmological examination every six months.
For people aged 70 years and older, a figure of 23-26 units is considered normal.
What is normal eye pressure for glaucoma?
Ocular pressure readings change dramatically when glaucoma occurs.
This disease can occur in one of four degrees of severity, which determines how much the indicator will increase:
- On initial stage disease, IOP can fluctuate from normal to exceeded by 4-5 units. Usually the pressure does not exceed 27 millimeters of mercury.
- In severe glaucoma, the value can be from 27 to 32 units.
- At a deep stage, the pressure rises to 33 millimeters of mercury.
- When IOP exceeds 33 units, they already speak of the final stage of glaucoma.
Intraocular pressure is measured during any routine ophthalmological examination, since based on these numbers, a specialist can draw conclusions about the presence of certain ophthalmic defects, even if they do not show any symptoms.
Useful video
In the video you will see clearly what IOP is:
The older a person is, the more often he needs to undergo examinations and be attentive to increasing IOP. Sometimes this is the only hint of diseases that need to be treated as early as possible.
Visual acuity: norm, diagnosis, disorders website 2019-01-30T14:11:34+03:00
Normal odds
The ability of the eyes to see separately and distinguish between two objects located nearby is called visual acuity. At normal indicators You can see two points at a distance of five meters. The distance between these points is 1.45 mm. If there is a decrease in visual acuity, then it will be impossible to successfully pass such testing.
Deviations from the norm (1.0) can occur naturally and are caused by aging of the body. However, vision often deteriorates sharply and decreases at a young age and even in children. The reasons for this are mass computerization and the emergence of various diseases.
Indicators below 1.0 - what does this mean?
In order to understand the reason for the sudden change, comprehensive examinations. An acuity score below 1.0 usually indicates advanced disease. The most common ailments include:
- Myopia. Focusing occurs in front of the retina. Changes in visual acuity reduce the ability to distinguish objects in the distance, a feeling appears fatigue, pain, headaches.
- Farsightedness. The focus of the image is behind the retina. Decreased visual acuity makes a person unable to see well at close range. Accommodation is impaired, blurred vision is observed, and strabismus occurs.
- Astigmatism. The reasons for the sharp decrease are irregular shapes of the lens or cornea. Images are distorted, objects appear in two, and headaches occur.
- Glaucoma. The disease appears due to abnormalities in intraocular pressure. When eye pressure decreases, deformation of the internal structure of the visual organ and retinal degeneration occurs. If optic nerve severely damaged, then with this diagnosis the disease leads to complete blindness.
- Cataract. There is clouding of the lens. As the disease worsens, the person begins to react painfully to light and has difficulty distinguishing colors. There are difficulties with reading and orientation at dusk.
The specifics of work can often lead to vision deterioration: improper working conditions, hazardous production, constant strain of attention. However eye diseases are also found in children. In this case, the loss of good vision is often associated with inherited ailments.
Basic Rules for Testing Eye Clarity
Visual acuity impairments are determined using special tables that display letters or numbers. The procedure is performed in an ophthalmologist's office or in specialized stores for the selection of glasses and lenses. Any first sign of an ocular disorder should prompt further diagnosis and treatment.
For an adult, tables with letters are used, for a child who cannot yet read, with symbols. The norm is when the 10th line out of 12 is clearly visible and readable. Based on such a diagnosis and further examination, it will be possible to understand what affects the deterioration of vision and what treatment will be optimal.
Basic verification rules:
- A man sits at a distance of five meters from the table.
- The images are located from the window on the opposite side.
- The 10th line of the diagram is located strictly opposite the eyes.
- The table must be illuminated with special lamps.
- Each eye is diagnosed separately - one is open, the other is closed, but not closed (this affects the severity of symptoms and the veracity of the results).
- You need to recognize a letter or sign within 2-3 seconds - more time will indicate a deviation.
How to do a home inspection
If you are interested in a decrease in human visual acuity, you can conduct a preliminary diagnosis at home. Various online tests will help with this, where the result is given at the end.
You can also use tables for checking, as in an ophthalmology office. Examples of tables can be found on the Internet and printed on a standard A4 sheet. The finished sheet with images is placed on the wall. A fluorescent lamp or two lamps (40 Watt) on the sides are installed above the table. The presence of the first changes and violations is indicated by the inability to examine the letters or symbols of the 10th line. In this case, you should immediately make an appointment with an ophthalmologist.
Dangerous symptoms
There are the first signs of vision deterioration, which may indicate the emergence and development of diseases:
Loss of visual acuity makes life joyless and causes the development of numerous pathologies. In order to detect deviations in a timely manner and successfully solve the problem, you need to visit an ophthalmologist regularly (at least twice a year). At risk are people with a genetic predisposition to diseases that were in the family.
Often, visual acuity decreases after trauma, for example, if the upper cervical vertebrae are damaged. Many ailments develop on the soil diabetes, cervical osteochondrosis transferred genetic diseases. The organs of the elderly are subject to changes. Timely access to a doctor and diagnosis is the most important step towards a speedy recovery.
