Causes and consequences of visual impairment and methods of compensation

Definition of vision

Man is endowed by nature with five senses that allow him to perceive the world around him.
Vision is a person’s ability to perceive information by converting the energy of electromagnetic radiation in the light range.

In order for us to see, our visual apparatus does a very complex job. The eye picks up optical stimuli, processes them into nerve impulses that are transmitted to the cerebral cortex, to the area responsible for processing them and forming a certain image. This complex process involves the extraocular muscles, the optical system of the eye, the structure of which includes the cornea, lens, iris and vitreous body, optic nerve and visual centers of the brain. If a functional failure occurs in any of these elements, it causes vision impairment. Damage to different structures manifests itself in different disorders.

A person receives more than 80% of information through vision. Visual impairment partially or completely deprives him of this opportunity. Visually impaired people are not uncommon these days.

Visual impairment

Types of visual impairment

Through the eyes, a person perceives almost 90% of information coming from the outside.
Therefore, complete or partial loss of vision significantly reduces the standard of living and is a dangerous factor in terms of domestic injuries and road accidents. However, it is known that eye diseases affect almost three billion people around the globe. And only one billion resorts to treatment or correction of various pathologies. All the many types of visual impairment can be divided into two main groups: functional disorders and organic disorders. Organic disorders are characterized by structural changes in various tissues of the eye and are often accompanied by impaired eye function. Such changes include conjunctivitis, cataracts, blepharitis, optic nerve atrophy, tumor lesions of the eyeball, etc. And functional disorders are changes in the course of light rays, with the help of which an image is formed on the retina. In other words, functional disorders are, first of all, a pathology of accommodation and refraction (farsightedness, myopia, astigmatism, amblyopia, or strabismus).

Classification of types of visual impairment

1. Refractive error is a decrease in the eye’s ability to clearly view objects distant from it at a certain distance.

2. Accommodation disorder is a disorder that is accompanied by the inability to clearly see objects located at different distances from the eyes (farsightedness or prebiopsia).

3. Disorder of lateral or peripheral vision is a change in which the ability to clearly see moving objects or objects located on either side of the eyeballs is lost.

4. Decreased eye adaptation. Characterized, for example, by a decrease or loss of the ability to adapt to different levels of illumination.

5. Impaired twilight vision, or night blindness. Characterized by the inability to see at dusk or in a darkened room due to dysfunction of special retinal cells - rods.

One of the most common visual impairments is myopia. The disease occurs when the eyeball is slightly longer than normal, so light rays are focused in front of the retina. This pathology is considered a functional disorder, since no organic pathologies or anomalies are observed in the eyeball.

Visual impairment

What are visual impairments?

In order to see, we must sense optical stimuli and process them into nerve impulses. Optical impulses are conducted to the cerebral cortex, where they are processed and image formed. This process involves the extraocular muscles, the optical system of the eye, consisting of the cornea, lens, iris and vitreous body, and its sensory cells, the optic nerve and the visual centers of the brain. If defects occur in the listed structures, this leads to deterioration of vision. including color and peripheral, and sometimes to blindness.

Impaired visual acuity

The most common causes of deterioration in visual acuity and the appearance of a “veil before the eyes” are changes in the eyeball or visual apparatus. For example, in myopic people the eyeball is not round, but oblong; in farsighted people it is flattened. The lens loses its ability to focus images, causing the image to form in front of the retina (in nearsighted people) or behind it (in farsighted people). Correction of these refractive errors is carried out by wearing glasses and contact lenses. Surgeries to correct myopia have been performed around the world for more than ten years using excimer lasers. Farsightedness is normal in newborns. Visual acuity may also deteriorate if brain function is impaired. For example, during migraine attacks, vision deteriorates. Often, visual acuity is reduced due to brain injury, and especially when consuming substances that act on the central nervous system, such as alcohol or drugs. Sometimes visual impairment occurs when there is insufficient blood supply to the brain, for example, if a person has not eaten for a long time, and this has led to a sharp decrease in blood glucose levels. Such visual disturbances quickly disappear after eating.

Flashes of light, narrowing of the field of view

If a person closes his eyes and sees flashes of light, “stars” or stripes, he should immediately consult an ophthalmologist. These symptoms suggest retinal detachment. It is also necessary to consult a doctor if the boundaries of the visual field of one or both eyes narrow, or a dark spot appears in the center of the visual field.

"Veil before the eyes"

As a result of the natural aging process, the lens of the eye and the vitreous body become cloudy. It is almost impossible to prevent this process. Sometimes clouding of the lens is observed in metabolic diseases (for example, diabetes), infection (jaundice), and cataracts.

Color blindness

There are many different forms of color blindness. Sometimes a person does not distinguish colors at all and sees everything in black and white. Sometimes color blindness is partial, i.e. applies to individual colors. As a rule, this is a congenital visual impairment, but it can also occur due to retinal detachment and dysfunction of the optic nerve.

Night blindness

A specific visual impairment is night blindness (nyctalopia). The retinal rods stop functioning and the person loses the ability to see in the dark. This disease is usually inherited, although it sometimes develops in older people.

In what cases should you contact an ophthalmologist?

Visual impairment should be regarded as a symptom of a dangerous disease and urgently consult an ophthalmologist. Timely medical assistance is especially important in case of retinal detachment or eye injury. Otherwise, serious visual impairment may occur. blindness.

The doctor will examine your eyes very carefully using a slit lamp, ophthalmoscope, or microscope. In some cases, he examines the visual field and measures eye pressure. All these studies are not dangerous and painless. Sometimes a medication that dilates the pupils is dropped into the eyes. This allows the doctor to better examine the fundus of the eye. After this procedure, you are prohibited from driving, reading or writing for several hours.

If you wear glasses, you should visit an ophthalmologist at least once a year to have your visual acuity checked. Wearing poorly fitting glasses can further impair your vision. Headaches and other ailments often occur.

Additional articles on this topic:

Types of visual impairment

A person’s eyes receive up to 90% of information coming from outside, so complete or partial loss of vision greatly worsens a person’s standard of living and contributes to a high risk of domestic injuries and road accidents. It is known that several billion people suffer from eye diseases, and only one billion have to resort to serious treatment or surgery.

There are several types of visual impairment. They can be divided into two broad categories - organic disorders and functional disorders.

Organic and functional visual impairments

With organic disorders, structural changes occur in the tissues of the eye, accompanied by deterioration of vision. Diseases that cause such changes include blepharitis. conjunctivitis. cataract. tumor diseases of the eye, optic nerve atrophy.

With functional disorders, there is a change in the path of light rays that form the image on the retina, therefore such disorders are primarily pathologies of refraction and accommodation, namely myopia. farsightedness. astigmatism. squint, etc.

Types of functional disorders

The eyes of a person diagnosed with refractive error are unable to clearly see distant objects. Refractive errors are one of the most common vision pathologies. Some experts claim that today about 30% of people have refractive errors. This pathology includes myopia, farsightedness, and astigmatism.

Accommodation impairment involves clearly viewing objects located at different distances.

Some people today are also diagnosed with peripheral or side vision disorders. In this case, the ability to consider objects that are on both sides of the eyes is lost.

A decrease in adaptation is accompanied by a decrease or loss of the ability to adapt to varying degrees of room illumination.

With night blindness, a person ceases to see normally in the dark due to dysfunction of the rods - retinal cells that are sensitive to light.

Most often, people are diagnosed with myopia. This pathology is a functional disorder, since no organic anomalies or pathologies of the eye are detected with it.

Visual impairment

Causes of visual impairment

Before we talk about the treatment of vision impairment, it is necessary to list the possible reasons why this problem most often occurs.

• Constant severe eye strain
  We will put this reason first, since it is by far the most common. In this case, the cells of the retina of the eye are negatively affected by too bright light, or, conversely, too dim lighting.

  Most often this happens as a result of a long stay at the computer, with very bright monitor lighting, especially when there is no or dim light in the room. As for situations where the cause of this tension is dim light, an example can be given of reading books on public transport in low light.

• Weakening of the lens muscles
  An equally common situation is when vision deterioration is caused by weakening of the lens muscles. The so-called focusing of the image occurs due to changes in the curvature of the lens. Depending on the distance to the object, the ciliary muscles control the convexity of a given crystal to focus the image. As a result of frequently looking at objects at the same distance, the muscles that control the curvature of the lens can become weak and sluggish, resulting in vision problems.

  Again, in most cases, this problem is caused by a long stay at the computer, in particular due to the fact that the person is constantly looking at the monitor at the same distance. This can also include watching TV, reading books, etc.

• Dryness of the mucous membrane of the eye
  Another reason why vision may deteriorate is dryness of the mucous membrane of the eye. As a result of the shell being in a dry state, clarity of vision is negatively affected.

  Drying of the eye membranes is caused by the fact that we blink very rarely, and it is with blinking that the eye membranes are moisturized and cleansed. Most often this occurs in cases where our gaze is focused on a certain object for a long time: a book, mobile phone and tablet, TV, monitor, etc.

  Read also:  Swelling, crow's feet and wrinkles under the eyes: how to get rid of the first age-related changes
• Poor circulation
  The retina is a truly amazing part of the eye, which plays a major role in our vision. Along with this “functionality”, the retina of the eye is very sensitive, especially its work depends on proper blood circulation. At the slightest disturbance in blood flow, she immediately reacts to this by deteriorating vision.

  In this case, the cause of deterioration in blood circulation is the internal causes of the body, which must be identified through examination and testing.

• Aging of the retina
  Ordinary aging of the retina can also lead to deterioration of vision. The cells of the retina of the eye contain a certain light-sensitive pigment, thanks to which we actually see. Over time, this pigment is subject to destruction, resulting in deterioration of vision. The reason for this is simple aging.
• Various diseases
  Various other diseases, especially those of viral origin, can cause visual impairment.

These are, in fact, all the reasons why vision deteriorates. Next, we will talk about the symptoms of vision impairment.

Symptoms of visual impairment

To begin to suspect that your vision is deteriorating, you should familiarize yourself with the symptoms that symbolize the presence of this problem.

• You begin to see poorly
  The first sign of deteriorating vision is that you begin to see worse. If earlier you could see certain objects well and clearly, now you cannot focus your eyes on them, and you see them blurry. Moreover, it is important to replace exactly which objects you have become worse able to see: those that are close, far away, or you see all objects poorly, regardless of their distance.
• Partial impairment of vision
  In this case we mean a situation where visibility deteriorates when you look in a certain direction. That is, for example, you see straight ahead well, but see poorly when you look away to the side. This also includes a situation where you cannot see well in a certain light.
• Pain in the eyes
  And one more symptom that we would like to mention here is pain in the eyes, when, for example, it occurs if you look at a bright light, or look at something for a long time and your eyes get tired.

What to do if your vision deteriorates?

If you notice that your vision is deteriorating, you urgently need to take all possible measures to stop it and prevent your vision from deteriorating further. Along with this, it is necessary to carry out a set of therapeutic actions that will help restore impaired vision. Let's look at the treatment of vision impairment in more detail.

• Consult a doctor
  First of all, if you have the slightest suspicion of vision deterioration, you should consult an ophthalmologist. The doctor will listen to your vision complaints, after which he will check it and perform an eye examination. If a doctor has his own medical office, then with the help of special computer diagnostics he will be able to study vision and the eyes themselves in more detail.
• Give your eyes a rest
  Regardless of what diagnosis the doctor made, nevertheless, you turned to him because of problems with your vision, and possible pain that you experienced in your eyes. That is why we recommend giving your eyes a rest for a while and not straining them. This is especially important to do if the doctor has diagnosed vision problems.

  To give your eyes a rest, eliminate, and if impossible, reduce to a minimum, working at the computer and watching TV. It is these 2 activities that most actively negatively affect vision. Instead, listen to music or the radio on a music center, or listen to audiobooks - whichever is more interesting. To distract yourself, you can go for a walk on the street, or go to a cafe with friends. At home, instead of watching TV, you can do household chores: general cleaning, rearrangement, revision of old things, laundry, etc.

• Do exercises for your vision and eyes
  In order to prevent vision from deteriorating and to promote its restoration, it is necessary to perform special exercises 3 times a day. Charging includes several simple exercises that are easy to perform.

  The first exercise is to switch vision: from near to far. To do this, take a pen and stand near the window. Hold the pen in front of you and alternate your gaze: first look at the pen, then look into the distance out the window, at some building or tree.

  The second exercise is called the “pendulum”, it consists in moving the handle in front of you, which should be at a distance of 30-50 centimeters, and focusing your vision on it. First, fix the handle straight in front of you, then move it to the left - focus your vision, then move it back to its original position - and again focus your vision, then move it to the right - and again focus your vision on the handle. These are two simple exercises that help the eyes with vision problems. The total duration of each exercise should be about 5-7 minutes.

• Take medications prescribed by your doctor
  When visiting a doctor, it is possible that he will prescribe some medications: eye drops, vitamin supplements, and in certain cases, he may recommend supplementing your diet with some foods. Follow the recommendations given to them and under no circumstances engage in self-medication, which may simply not be effective, and in some cases, harmful.
• Lead a healthy lifestyle
  Oddly enough, but, nevertheless, a healthy lifestyle will have a positive effect on your vision. A healthy lifestyle consists of a number of measures that must be followed not only in case of deterioration of vision, but in life in general.

For good vision, healthy sleep is necessary so that the eyes can fully rest and relax from constant stress. It is important to adhere to a daily routine so as not to sit all night long in unison at the computer. Stick to a proper and balanced diet, which will be rich in all the vitamins necessary for health, including vision. Along with proper nutrition, consume fruits and vitamin preparations that are responsible for vision, these in turn are vitamins: A, B2, C, E, as well as zinc, lutein, lycopene and beta-carotene. Finally, we strongly recommend giving up bad habits: alcohol and smoking.

Prevention of visual impairment

How to stop vision deterioration? Unfortunately, many of us think about preventing visual impairment quite late, when it has started to worsen. However, the recommendations below will help stop the problem, and if everything is fine with your vision, prevent this problem.

• Take breaks from work
  As you may have noticed, one of the most important problems with visual impairment is the computer and TV. That is why, when working at the computer for a long time and when watching TV for a long time, it is very important to take breaks every 2 hours. Such breaks should last 15-20 minutes. At this time, you can either do exercises for your eyes or simply look out the window to switch to distant vision. You can also just lie down with your eyes closed. In general, it is best to try to spend as little time as possible on the computer and TV.
• Do exercises for your eyes
  A little higher in our article, we talked in more detail about the benefits of gymnastics for the eyes and gave an example of several exercises. Do these exercises 3 times a day and your eyes will thank you.
• Adequate sleep is very important.
  Your sleep should last about 6-8 hours, this will help rest your eyes, especially after severe overexertion.
• Use special protective equipment
  If your work involves a computer or you simply spend a lot of time on it, we recommend purchasing special safety glasses that protect your eyes when working on a computer.
• Take vitamins for vision
  A certain amount of vitamins contained in the body is responsible for vision; their balance should always be normal. Today there are special vitamin complexes that include all the vitamins necessary for vision. Taking these vitamins reduces the risk of vision impairment.

Take care of your vision and try to prevent its deterioration, as it is very difficult to restore!

Sources: https://www.budemzdorovy.org, https://doktorland.ru, https://comp-doctor.ru, https://domadoktor.ru/179-narushenie-zreniya.html

Next:

• Diagnosis of visual impairment

Types of violations

Let's look at the main and most common types of visual impairments.

Myopia

With myopia, a person has difficulty distinguishing objects at a distance. The higher the degree of myopia, the weaker he sees into the distance. With myopia, the image of an object is focused not on the retina, but in front of it. This may be due to curvature of the cornea, elongation of the eyeball, or both. Most often, myopia is detected in adults who spend a lot of time at the computer and in school-age children, since at this time the load on the eyes increases several times. This disorder can be corrected with glasses and lenses, as well as through surgery.

Minor visual impairment can be corrected with special visual exercises.

Farsightedness (hypermetropia)

Farsightedness is caused by abnormal curvature of the cornea, insufficient eyeball size, or both. With hypermetropia, the image is projected not on the retina, but in the plane behind it. With moderate and high farsightedness, the image will be blurry both near and far. This disorder often occurs in childhood, but does not always indicate weakened vision. Children's farsightedness is normal when it is caused by the small size of the eyeballs. As the child grows, the pathology goes away on its own, but the process needs to be monitored by regularly visiting an ophthalmologist.

Astigmatism

With astigmatism, the surface of the eyeball becomes oval, like a rugby ball. Normally, the eye has an absolutely round surface. This visual impairment is expressed by improper focusing. Rays of light passing through the eye are projected on the retina at two points, making objects blurry.

Astigmatism often develops in childhood, usually at the same time as farsightedness or nearsightedness. If left uncorrected, this disorder can cause a sharp decrease in visual acuity and also cause strabismus.

Strabismus (strabismus)

Strabismus is the deviation of one of the eyes from the common point of fixation, which makes it impossible to merge two images into one. Strabismus occurs due to decreased visual acuity in one or both eyes or due to impaired refraction and accommodation.

Treatment of strabismus in adults is described here.

Amblyopia

This disorder is popularly called “lazy eye.” It develops when there is a difference in the refractive ability of the eyeballs or is caused by congenital anomalies of one of them, and is also a consequence of untreated strabismus. As a result, a fuzzy image is transmitted to the brain, and it simply suppresses the work of one eye. In this case, there is a deterioration in visual acuity.

Child with ablyopia

If amblyopia is left untreated, visual acuity will deteriorate.

Features of visual impairment

Myopia and farsightedness

Normal vision is called proportionate, or emmetropic. Myopic people (myopes) see close objects well, distant objects poorly, and farsighted people (hypermetropes), on the contrary. Almost two thirds of all humanity are farsighted or nearsighted, that is, they have ametropic eyes.

In myopic people, due to the increased power of refractive media due to the increased size of the eyeball, light rays from distant objects are focused in front of the retina. As a result, a clear image is not obtained in the area of ​​the macula, and distant objects are seen blurry. But rays of light from close objects in a myopic eye converge precisely on the retina and give a clear image without strain or with minimal strain during accommodation. Myopic people can read for hours and work with very small details without experiencing visual fatigue.

Farsighted eyes, on the contrary, are characterized by weak refractive power or insufficient dimensions along the anterior-posterior axis. Light rays from distant and close objects in such an eye are refracted less than necessary, and a clear image on the retina is not obtained, since the focus is behind the retina. These changes in the focusing conditions of the image in the eye are called refractive.

For far-sighted and near-sighted people, vision is improved with glasses. A convex glass placed in front of the far-sighted eye increases the refractive power of the eye, the focus of light rays is transferred precisely to the retina, and the eye works with less strain. Concave glass placed in front of the myopic eye reduces its refractive power, rays from distant objects converge in the yellow spot - distance vision improves. The use of glasses, however, inevitably leads to a weakening of the internal muscles of the eye, and therefore, over time, the glasses have to be replaced with stronger ones.

Accommodation

The ability of the eye to accommodate is examined using the so-called ocular ergography, which makes it possible to accurately determine the degree of visual fatigue. Ergography has also proven to be a valuable method for identifying disorders of dynamic refraction of the eye in myopic children and adolescents; it is used to evaluate the vision of persons engaged in delicate and precise production operations.

Accommodation of the eye is the most important regulator of vision function. With age, its degree gradually decreases, because the lens itself becomes less elastic. A phenomenon called presbyopia, or senile farsightedness, occurs. Due to weakening of accommodation, a person tends to move a book or newspaper away from his eyes (to facilitate the work of the ciliary muscles) or resorts to glasses with convex lenses.

Astigmatism

Astigmatism is a distortion of the image by an optical system due to the fact that the refraction or reflection of rays in different sections of the passing light beam is not the same. As a result, the image of the object becomes blurry. Each point of the object is depicted as a blurred ellipse.

According to the degree of violations

The degree of visual impairment is determined by the level of decrease in visual acuity - the ability of the eye to see 2 luminous points with a minimum distance between them. Normal visual acuity, equal to one - 1.0, is taken to be a person’s ability to distinguish letters or signs of the tenth line of a special table at a distance of 5 meters. The difference in the ability to distinguish characters between the next and the previous lines means a difference in visual acuity of 0.1.

There are several groups of people with visual impairments:

• Blind people are people with a complete absence of visual sensations or with residual vision, as well as retaining the ability to perceive light.
• Totally blind are persons with a complete absence of visual sensations.
• Partially blind people are people who have only light perception.
• Visually impaired - persons with visual acuity from 0.05 to 0.2. Their difference from the blind is that with a pronounced decrease in the acuity of perception, the visual analyzer remains the main source of perception of information about the surrounding world and can be used as a leader in the educational process, including reading and writing.

Depending on the time of appearance of the defect, there are 2 categories of blind people:

1. Born blind are people with congenital total blindness or who became blind before the age of 3 years. They have no visual ideas, and the entire process of mental development is carried out in conditions of complete loss of the visual system.
2. Blind people are people who lost their sight in preschool age and later.

Presbyopia

The normal functioning of the visual apparatus is disrupted due to the aging of the lens. The eyes lose the ability to view objects at different distances. This disorder occurs most often in patients aged 40-50 years. The mechanism of development of the pathological process is quite simple. The core of the lens becomes denser, loses transparency, and its ability to correctly refract light rays deteriorates.

Symptoms of presbyopia:

• painful sensations in the eyeballs;
• headache;
• increased eye fatigue;
• mild photophobia;
• lacrimation;
• blurry picture;
• deterioration of visual acuity.

Prevention of the disorder involves dosing visual stress, choosing lighting fixtures responsibly, and regularly performing eye exercises. An important factor is a balanced diet. The menu should contain products that contain chromium, zinc, magnesium and other trace elements. To correct the disorder, contact lenses, glasses, and laser techniques are used. If the lens does not work properly, it is replaced with an artificial one.

WHY IS VISION IMPAIRED?

The eye is an organ of perception that serves us faithfully throughout our lives, so deterioration in the functioning of the eye must be treated with great attention. Knowing the causes of visual impairment, you can cure the first symptoms of diseases in time.

If your vision begins to deteriorate, then you need to urgently go to the doctor. The fact is that in addition to direct eye diseases, the quality of vision can be affected by diseases that affect the nervous system or blood vessels of the eyeball, as well as various pathologies of the tissues around the eyes.

Watery eyes are one of the first signs that your vision needs help. In addition, “floaters”, loss of clarity, pain and redness pose a danger.

HOW DOES INTERFERENCE OCCUR IN THE EYE?

The eye is a complex optical device. Before a picture is formed in the human brain, light must go through several stages. Violations that occur in at least one of them can lead to a deterioration in the quality of images received from the outside. Thus, most problems with visual acuity are associated with pathologies of the retina.

Visual acuity is the ability of the eye to distinguish between two points at a certain distance. It is measured in conventional units: for a healthy eye, visual acuity is equal to one.

If there are obstacles in the path of light to the retina, visual acuity decreases. For example, if negative changes occur in the lens or cornea, a person’s vision may become blurred, and spots often appear before the eyes in such cases.

If the lens is shaped incorrectly, the positioning of the image on the retina is deformed, which leads to poor image quality. With weakened eye muscles, as well as overgrown fatty tissue of the eye, double vision and distortion of visible images are possible.

After light hits the retina, certain nerve impulses are immediately sent to the brain. Therefore, if there are any disturbances in the functioning of the nervous system, a person experiences distortions in visual images. As a rule, they are quite specific depending on the specific nervous disorder (even false images - hallucinations).

FATIGUE IS THE CAUSE OF VISION PROBLEMS

The pace of modern life is constantly accelerating. A person is required to quickly respond to various challenges, as well as absorb a huge amount of information throughout the day. Most new information enters the brain through the eyes.

Therefore, very often there are cases when vision is impaired not because of diseases of the lens or retina, but because of severe and constant overwork, lack of sleep, stress and prolonged visual strain that occurs in a person when working at a computer.

If you notice that visual acuity decreases towards the end of the day, if your eyes become red and hurt, then to eliminate unpleasant symptoms you need to relax, have a good rest and do special exercises for the eyes.

If you are concerned about how to preserve your vision for a long time, it is recommended that you immediately visit an ophthalmologist at the first signs of visual impairment to exclude the possibility of developing dangerous diseases. After all, eye ailments are a serious problem that should not be taken lightly.

DISEASES CAUSING VISUAL IMPAIRMENTS

The retina is most often affected - vision deteriorates due to the following pathologies:

• retinal detachment;
• mauclodystrophy – lesions of the retinal area with the largest number of receptors;
• vitreous detachment;
• retinal tear;
• diabetic retinopathy – damage to the small vessels of the eye and impaired blood supply to the eyeball.

When the lens is damaged, visual impairment is caused by the following diseases:

• cataract (clouding of the lens);
• myopia;
• farsightedness.

Source https://www.proboxs.ru/novosti/zdorove/osnovnye-prichiny-narusheniya-zreniya.html

Astigmatism

This disease is accompanied by a violation of light refraction. The structure of the cornea (and sometimes other parts of the organ) changes. As a result, the image is focused not in the form of a point, but in the form of a straight line. In a healthy person, the cornea and lens are shaped like a sphere. As this disorder develops, the surface becomes deformed. Different meridians of the corneal surface develop their own refractive power, and the image when light passes through such a defective cornea turns out to be distorted.

A patient diagnosed with astigmatism does not see a complete image, but a distorted picture, which consists of clear and blurry lines. Scientists say that every 6th person on the planet suffers from astigmatism. The violation has different degrees of severity.

• 0.5DD. It has virtually no effect on the sharpness and clarity of vision; astigmatism is divided into congenital and functional. No correction is required.
• 1 DD and above. The person experiences severe visual discomfort. After diagnostic measures, a correction is prescribed. Ignoring this disorder can lead to the development of strabismus.

Astigmatism is classified into simple, complex and mixed depending on the specific changes in refraction. With simple vision in one meridian is within the acceptable norm, and in the other there is a violation of the process of focusing the image on the retina. In complex cases, pathological changes are observed in both meridians, but they are expressed differently. Mixed is when there is myopia in one meridian and hypermetropia in the other.

The disease has three stages of development:

• up to 3 diopters – weak;
• 3-6 diopters – average;
• from 6 diopters – high.

In ophthalmological practice, several methods are used to correct vision for astigmatism. Of course, the safest and most effective is the implantation of phakic lenses. The technique has a minimal number of contraindications and involves the installation of special implants into the eye structure. The advantages of this method include minimally invasiveness, safety, instant results, no rehabilitation period, and a minimum of restrictions after installing intraocular lenses.

You can correct your vision with toric contact lenses or glasses. In this case, the patient must go through an adaptation period until the brain gets used to the new image. And another technique is laser correction.

Vision problems in children

Good vision is an indispensable condition for the health and full development of a child. It is through vision that a child acquires basic communication skills, forms an idea of ​​the world around him and his own vision. This is where the development of the child’s personality begins.

If a child's visual acuity is reduced, the baby's development can be significantly hampered, so questions about children's vision are extremely important. Vision problems in a child primarily affect parents, because they are responsible for the health of their child. Under no circumstances should these problems be allowed to arise.

Causes

It is impossible to treat visual impairment in children if you do not know their causes. So, the main factors of visual impairment in children are:

• Hereditary predisposition;
• Stress;
• Reduced hemoglobin level;
• Poor visual hygiene (reading in low light conditions, reading or playing on a mobile phone while lying down, working on a computer, etc.);
• Failure to comply with visual safety rules: manipulation with sharp objects, addiction to looking at bright light without glasses.

The most common vision disorder in children is myopia. This is due to the fact that the age from 7 to 15 years is combined with increased visual stress (reading, writing, school lessons). Failure to follow the rules of watching TV and working with a computer, genetic predisposition, nutritional deficiencies and other negative factors can lead to the development of strabismus, myopia, amblyopia and other vision problems in children.

Any visual impairment or eye disease in a child requires immediate medical attention. Remember: the earlier treatment is started, the greater the chances of a full recovery and no problems in the future, regardless of the cause of visual impairment in children. Preserving children's vision is an important responsibility of parents.

Features of psycho-emotional development

Deficiencies in visual perception lead to the formation of fuzzy, unclear images and ideas in the child, and negatively affect the development of mental operations (synthesis, analysis, comparison, generalization, etc.), which leads to difficulties when studying at school and mastering educational material. In addition, visual impairment significantly narrows the scope of sensory cognition, thereby affecting the general qualities of emotions and feelings, their significance for life, and therefore the formation of a person’s personal qualities. Children often feel doomed and useless, and this depressed state leads to slower intellectual growth.

Psychologists note that children with visual impairments have the following specific features:

• They have an increased personal level of anxiety;
• Children have a poorly developed emotional-volitional sphere;
• Poor correlation of emotion with facial expression;
• Insufficiently competent in expressing emotions;
• Poorly understand the facial expressions of other people's emotions.

Features of physical development

Visual impairment in children complicates spatial orientation, delays the formation of motor skills, and leads to a decrease in motor and cognitive activity. Some children experience a significant delay in physical development: the correct posture when walking, running, natural movements, and outdoor games is impaired, coordination and accuracy of movements are impaired.

Visual impairment leads to secondary deviations in the physical development of children. Many children with visual impairments have a low level of development of tactile sensitivity and motor skills of the hands and fingers.

Due to the absence or sharp decrease in vision, children cannot spontaneously, by imitation of others, master various objective and practical actions, as happens in children with normal vision. Because of this, the arm muscles become sluggish or, conversely, too tense. All this leads to a low level of development of tactile sensitivity and hand motor skills and negatively affects the formation of subject-related practical activity.

Causes and consequences of visual impairment and methods of compensation

Visual impairments can be congenital or acquired.

Congenital blindness is caused by damage or diseases of the fetus during intrauterine development or is a consequence of the hereditary transmission of certain visual defects.

Acquired blindness is usually the result of diseases of the visual organs - the retina, cornea and diseases of the central nervous system (meningitis, brain tumor, meningoencephalitis), complications after general diseases of the body (measles, influenza, scarlet fever), traumatic injuries to the brain (head wounds, bruises) or eyes .

There are progressive

and
non-progressive
disorders of the visual analyzer. With progressive visual defects, a gradual deterioration of visual functions occurs under the influence of the pathological process. For example, with glaucoma, intraocular pressure increases and changes occur in the tissues of the eye. Vision decreases with the appearance of brain tumors. If sanitary and hygienic conditions for writing and reading are not observed, myopia and farsightedness progresses.

Non-progressive defects of the visual analyzer include some congenital defects, such as astigmatism and cataracts. The causes of these defects can also be the consequences of certain diseases and eye surgeries.

So, dysfunctions of the visual analyzer can occur in children both during intrauterine development and after birth. Therefore, there are such categories of children with visual impairments as those born blind, those who became blind early, and those who lost their sight after three years of life. This differentiation is based on the fact that the time of vision loss is very important for the subsequent development of the child. For example, people born blind do not have visual images in their memory, which blind people have in varying degrees and volume.

The time of onset of a visual defect is essential for the mental and physical development of the child. The earlier blindness occurred, the more noticeable are the secondary deviations, psychophysical characteristics and uniqueness of psychophysical development. The mental development of people born blind has the same patterns as that of sighted children, but the lack of visual orientation affects most noticeably the motor sphere and the content of social experience. A kind of landmark

For a blind person, the reaction to sound is the same as for a normally sighted person at an early age, a reaction to sound stimuli, but for a blind person, sound becomes the main factor of orientation.

Loss of vision forms the uniqueness of the emotional-volitional sphere, character, and sensory experience. The blind have difficulties in playing, learning, and mastering professional activities. At an older age, people with impaired vision experience everyday problems, which causes complex experiences and negative reactions. In some cases, the uniqueness of the character and behavior of the blind affects the development of negative character traits in them: uncertainty, passivity, a tendency to self-isolation; in other cases - increased excitability, irritability, turning into aggressiveness.

The development of higher cognitive processes (attention, logical thinking, memory, speech) in people born blind proceeds normally. At the same time, a violation of the interaction of sensory and intellectual functions is manifested in a certain originality of mental activity with a predominance of the development of abstract thinking.

The difference between blind children and those born blind depends on the time of vision loss: the later the child lost his vision, the greater the volume of visual ideas he has, which can be recreated through verbal descriptions. If you do not develop visual memory, partially preserved after loss of vision, a gradual erasure of visual images occurs.

A blind child has every opportunity for a high level of psychophysical development and full knowledge of the world around him, relying on a intact analytical network. In the conditions of special training, adequate techniques and methods of using auditory, skin, olfactory, vibration and other analyzers are formed, representing the sensory basis for the development of mental processes. Thanks to this, higher forms of cognitive activity develop, which are leading in the compensatory restructuring of perception.

The system of compensatory restructuring at the initial stage of learning creates conditions for the correct reflection of the surrounding world in a visually effective form, and as social and everyday experience accumulates, in a verbal and logical form with the help of intact analyzer systems in the body of a blind child.

Compensatory restructuring largely depends on the preservation of vision. Even minor remnants of vision are important for orientation and cognitive activity of persons with profound visual impairments.

L. S. Vygotsky pointed out that the blind have a so-called sixth sense (thermal), which allows them to notice objects at a distance and distinguish colors using the sense of touch.

In the learning process, teachers and adults (parents) should proceed from the fact that compensation for blindness begins in a child from the first months of his life.

Compensation for blindness, L.I. Solntseva points out, is a holistic mental formation, a system of sensory, motor, and intellectual components that provides the child with an adequate and active reflection of the outside world and creates the opportunity to master various forms of activity at each age stage.

Visually impaired people have some opportunity to use their existing vision when getting acquainted with phenomena, objects, as well as in spatial orientation and movement. Vision remains their leading analyzer. However, their visual perception is only partially preserved and is not entirely complete. Their overview of the surrounding reality is narrowed, slow and inaccurate, therefore their visual perception and impressions are limited, and their ideas have a qualitative originality. For example, a visually impaired person has impaired color perception, the color characteristics of the perceived shade are depleted. With pronounced myopia and farsightedness, a visually impaired person may not notice some externally weakly expressed signs that are important for characterizing an object.

For the visually impaired, strabismus makes it difficult to see with both eyes, i.e., binocular vision is impaired. In the conditions of early special education, shaped, spatial and stereoscopic vision develops and improves, which in the future ensures the formation of complex spatial concepts.

Among the visually impaired, there are a large number of people with impaired color discrimination functions and contrast sensitivity of vision, and there are congenital forms of pathology of color perception.

The perception of objects and their images is influenced by a violation of oculomotor functions, which causes difficulties in fixing gaze, tracking dynamic changes, and assessing linear and conditional quantities.

Corrective work is therefore aimed at using special techniques and methods for observing phenomena and objects based on hearing, touch, and smell, which allows children to form complex synthetic images of reality.

The residual vision of a visually impaired person is essential for his development, educational, work and social adaptation, therefore it must be carefully protected: regular diagnostics and periodic consultations with an ophthalmologist, typhology teacher, and psychologist are necessary.

The sense of touch is of great importance in the perception and knowledge of the surrounding reality for the blind and visually impaired. Tactile perception provides a complex of various sensations (touch, pressure, movement, heat, cold, pain, texture of material, etc.) and helps determine the shape and size of a figure, and establish proportional relationships. Various sensations perceived by the nerve endings of the skin and mucous membranes are transmitted to the cerebral cortex in the department associated with the work of the hands and fingertips. This is how the blind and visually impaired learn to “see” with their hands and fingers.

Along with touch, auditory perception and speech play an important role in various activities for the blind and visually impaired. Differentiated auditory perception and vocal reactions when getting acquainted with objects, which emerged at the first stage of the blindness compensation system, become increasingly significant as a means of communication with surrounding people. A blind child uses sounds and words to attract attention to himself. An adequate reaction from an adult stimulates the child to have an emotional attitude towards this.

With the help of sounds, blind and visually impaired people can freely determine the objective and spatial properties of the environment. They can determine the source and location of a sound with greater accuracy than sighted people. The high level of development of spatial hearing in people with visual impairments is due to the need to navigate in a diverse sound field.

Therefore, in the process of training and education of the blind and visually impaired, differentiation exercises are carried out - distinguishing and assessing the nature of an object using sound, analyzing and assessing a complex sound field: sound signals are inherent in certain objects, devices, mechanisms and are a manifestation of the processes occurring in them.

The success of persons with visual impairments in mastering various types of activities: subject-matter, play, work, educational activities depends on a high level of development of visual-figurative Concepts, spatial thinking, and spatial orientation.

Spatial orientation is an essential part of free movement in space. Ability to endure

direction, determining one’s place in space, overcoming or bypassing obstacles - all this presents difficulties for a blind person due to the impairment of the ability to visually perceive and analyze space. The various structures of the psychological system that develop in blind people of different ages are

basis for effective correction of defects in their spatial orientation.

Teaching spatial orientation to blind children of preschool and school age shows that the process of its formation is multi-level and is associated with the development and improvement of integrative processes, the ability and ability of blind children to holistically and generally perceive the surrounding space, analyze it using both specific, individual and generalized landmarks , filling the space.

Vision problems in adults

All hereditary disorders in the human body, including the organs of vision, are transmitted from one of the parents, often through a generation, and congenital ones develop already during the development of the fetus in the womb. Acquired disorders appear after birth due to a number of reasons.

The following are eye diseases that occur most often in adults:

• Amblyopia (described above in the article);
• Cataract. This vision pathology is a clouding of the lens, which could arise as a result of various infections suffered during intrauterine development, metabolic disorders, and also due to genetic disorders. Cataracts are one of the leading causes of blindness in both adults and children, with their prevalence doubling every 10 years after age 40.
• Glaucoma. This visual impairment has a characteristic symptom of visual impairment - increased intraocular pressure. Glaucoma can cause loss of all fields of vision in a person, as well as the death of the optic nerve itself. That is why timely diagnosis and treatment of this disease is important.

What symptoms of cataracts can be found here. And also read about the treatment of glaucoma with a laser in the article.

Farsightedness

Farsightedness or hypermetropia is a refractive error of the visual system when the image is focused behind the retina. The main reason for the development of the pathological process is shortening of the eye axis. Farsightedness can also occur when the refractive power is weakened.

Degrees of farsightedness:

• up to +2 DD – weak, accompanied by headaches and severe visual fatigue, while vision is normal;
• up to +5 DD – average, a person sees well far away, but poorly up close;
• above +5 DD – strong, poor vision, difficult to see even those objects that are located nearby.
• To prevent the occurrence of this disorder, regularly visit the ophthalmologist's office and have your vision checked. The following measures are also excellent prevention:
• correct choice of lighting devices, for example, the power of a table lamp should not exceed 100W;
• alternating loads and rest;
• gymnastics for the eyes (a set of exercises to develop the muscles of the visual apparatus);
• timely diagnosis and competent selection of correction method;
• massage, swimming;
• balanced diet.

To restore clarity of vision to the patient, intraocular lenses are installed in the eye. They are made of biocompatible, high-quality material and are not rejected by the body. Implants immediately improve vision; a couple of hours after installing the lenses, you can go home. The list of contraindications is minimal. Side effects are extremely rare.

Correction of the disorder can be carried out in other ways, for example, using glasses or contact lenses. You can also resort to laser correction, but this will take a long time, since after the operation there is a long rehabilitation period.

Prevention of visual impairment

It is not always possible to prevent visual pathologies, but a person can reduce the likelihood of their development. To do this, you need to systematically visit an ophthalmologist, take vitamins for the eyes, take breaks when working at the computer, maintain visual hygiene, perform a set of eye exercises daily, and promptly treat ophthalmological diseases. A healthy lifestyle, including proper nutrition and exercise, also prevents the development of visual pathologies.

Today, a person does not always manage to lead just such a lifestyle. Not every person succeeds in eating a balanced diet.

You can compensate for the lack of certain substances in the body with the help of vitamins and special supplements.

In any case, maintaining health must be approached comprehensively. This approach will be the key to good vision.

Causes

Good vision depends not only on the eye, but also on its interaction with the brain. The causes of visual impairment are divided into 3 groups:

1. Damage to parts of the eye or structural abnormalities.
2. Refractive error occurs when the eye is unable to focus an image on the retina.
3. Damage to the part of the brain that is responsible for interacting with the eye.

Factors that can cause visual impairment:

• Active mental activity leading to overstrain of the eye muscles and nerves. It is known that in the absence of the required amount of rest, all these systems begin to work worse and vision decreases.
• Long work at the computer. In this case, the person blinks less often, so the eyes do not receive the necessary moisture. It is also worth remembering about the blue light that comes from the monitor. A number of studies have confirmed that it can have a negative effect on the retina.
• Poor or very bright indoor lighting. Lack of light, as well as its excess, have a negative effect on vision.
• The bright sun can damage the retina, and the absence of light can cause great eye strain and provoke the development of myopia.
• Drinking alcohol and smoking. Toxins contained in alcoholic beverages and nicotine negatively affect the health of the entire body. In particular, they impede blood circulation in the vessels of the eye, which leads to insufficient oxygen supply to the tissues and impaired vision.
• Poor nutrition. A diet high in fat and fast carbohydrates, and almost devoid of the vitamins found in fresh fruits and vegetables, deprives our eyes of the nutrients necessary for normal vision.

Features of psycho-emotional development

The psyche of blind and visually impaired people does not differ significantly from the psyche of normally sighted people, but it has some peculiarities due to the enormous role that vision plays in the processes of reflection and control of activity.

Visual impairment and its extreme form - blindness - significantly narrows the scope of sensory cognition and can affect the degree of manifestation of certain emotions, their external expression and the level of development of certain types of feelings. Many researchers note that blindness entails changes in the nature of emotional states towards the predominance of asthenic moods of sadness, melancholy, or increased irritability and affectivity that suppress the individual’s activity. Such conclusions were made in the course of studies of late-blind people who are seriously experiencing the loss of vision, as well as people born blind and early blind.

Features of physical development

Loss or profound impairment of vision function primarily affects the fundamental property of human reflective activity - activity. Visual impairments especially significantly complicate orienting and search activities. This phenomenon is explained by the fact that the development of activity depends not only on the ability to satisfy the need to know everything around, but also on external influences that contribute to the emergence of a motive for orienting activity. The number of such impacts on visually impaired and especially blind people is sharply reduced due to impaired visual functions and the resulting limited ability to move in space.

WHAT CAUSES VISUAL DISORDERS

To understand the root causes of visual impairment, we need to look at how muscle tension and contraction occurs.

Harry Benjamin (the one who got rid of his -20 using the Bates method) identifies THREE main reasons:

MENTAL and MENTAL TENSION

Dr. Bates states quite definitely that he believes that the cause of all visual disturbances is mental, mental stress, which, accordingly, generates physical tension on the eyes and ocular muscles and nerves, thus leading to visual disturbances.

He believes that nervous character is the cause of most serious defects of vision.

Bates introduced relaxation as a treatment method that proved his theory. Moreover, as a release of mental stress, to relieve tension from the eyes (along with the muscles and nerves associated with them). And vice versa: relax the muscles and nerves of the eyes, which leads to relaxation of the mind (and brain).

Thus, one can see the importance of the ability to relieve tension, both mental and physical. Only under these conditions is it possible to achieve good treatment results. Some cases of failure may well be explained by the patient's inability to relieve tension sufficiently or by neglect of physical relaxation.

Any factor, not only mental, but also physical, that can cause tension in the eye muscles is a potential cause of visual impairment.

Why does mental stress occur? Bates talks about many reasons, such as LACK OF INTEREST in what you want to see. Like schoolchildren... They are not interested in the subject, they are tired, but they need to see what is written on the board!

Bates also became convinced in practice that LIES are the cause of myopia and farsightedness. Because when a person simply tells the truth, he is absolutely relaxed, but in order to lie, effort is required, and even a false thought creates tension in the eyes! (he specifically checked changes in vision with sincere and deceitful answers to questions posed using a special device)

In general, in principle, in order to see into the distance, the eyes should be RELAXED, and close ones should be tense. And mental stress affects the eye in the same way as physical stress. This is how the habit of looking into the distance with tension appears.

NUTRITION

When looking for possible reasons for the tense state of the eye muscles, it should be borne in mind that the eye is part of the body and therefore depends on the state of the body as a whole.

Diseases such as diabetes and nephritis are known to affect the eyes, and there is medical recognition that diabetes is at the root of some cases of cataracts. Most non-specialists know that spots appear and “float” before the eyes due to liver diseases and digestive disorders.

But the close connection between the eyes and OTHER PARTS OF THE BODY is fully confirmed by those who study iridology.

The pioneers of iridology did a great deal of work to show that any change, functional or organic, in any part of the body or organ is reflected in the eyes, changing the color of the part of the iris that is directly related to that part of the body or organ.

This miraculous demonstration is the result of the relationship between the nerves of the eye and the central nervous system. If the eyes are affected by changes in individual organs, then how much does this influence increase when the WHOLE ORGANISM is involved?

Many natural practitioners have discovered that inflammatory conditions of the eyes, such as conjunctivitis, iris inflammation, etc., should not be considered as diseases affecting only the eyes and nothing else, but as a symptom of a general imbalance in the body due to excessive consumption of sugar, protein, etc.

Experience has shown that poor nutrition affects not only the eyes themselves, but also the processes by which vision is achieved, because the muscles and blood vessels surrounding the eyes also draw in waste products - a consequence of poor nutrition.

Once the muscles and blood vessels become clogged, proper removal of waste becomes impossible and the muscles, instead of being soft and flexible, become stiff and tight.

All this ultimately interferes with normal accommodation and then, as a direct consequence, affects the shape of the eye. The end result is visual impairment.

The cause of many cases of nearsightedness, farsightedness and astigmatism is none other than all of the above, and senile farsightedness is almost entirely due to this.

Until recently, it was believed that when a person reaches middle age, the eyes naturally change their shape, thus making it difficult to see close objects normally and causing senile farsightedness.

This is seen as an inconvenient but necessary price that we are forced to pay for being in this world for so long. And this difficulty is eliminated by wearing convex glasses.

Few of the millions of people suffering from farsightedness realize that poor nutrition for 45 or 50 years may be responsible for these changes in their visual abilities.

But there is no doubt that many people suffering from farsightedness can restore normal vision simply by following a reasonable diet and doing a few simple eye exercises.

To emphasize the vital relationship between nutrition and vision, it should be noted that there are many documented cases of healing of visual impairment through simple fasting, which helps to remove harmful substances from the muscles and blood vessels of the eye, as a result of which the muscles relax and vision improves.

When is disability granted?

Poor vision and the inability to cope without outside help are also one of the reasons why a person is given a disability.

Determining the visual disability group is the prerogative of the ophthalmologist.

Disability group I is established for the fourth degree of visual impairment. The criteria for this degree are complete blindness (zero vision in both eyes); visual acuity of the better seeing eye is not higher than 0.04 diopters; narrowing of the boundaries of the field of view of both eyes to 10-0° from the point of fixation.

Disability group II is established with the third degree of impairment in the functioning of the visual analyzer. Its criteria are:

• visual acuity of the better seeing eye from 0.05 to 0.1;
• narrowing the boundaries of the visual field of both eyes to 10-20° from the point of fixation.

With the second group of disability, a person’s work activity is possible only in specially created conditions. Usually these are societies for the blind, where people do work with their hands.

Okulohel eye drops with instructions

Trusopt eye drops for glaucoma and eye pressure are presented in this article.

This article will tell you what to do if barley appears on the eye.

The third disability group can be established for the second degree of visual impairment, which is characterized by:

• decreased visual acuity of the better-seeing eye from 0.1 to 0.3;
• unilateral narrowing of the boundaries of the visual field less than 40° and no more than 20° from the point of fixation.

Disabled people of the third group are visually impaired people.

Minor citizens with 1-3 disability groups are assigned the status of “disabled child”.

Estimated indicators

It is estimated that approximately 1.3 billion people worldwide live with some form of distance or near vision impairment. In distance vision, 188.5 million people have mild visual impairment, 217 million have moderate to severe visual impairment, while 36 million people are blind (1). In terms of near vision, 826 million people live with this type of vision impairment (2). As the population grows and ages, there will be an increasing risk that more people will develop visual impairment.

conclusions

Thus, a visual impairment is a physical or psychological defect that entails some deviations from normal development. Congenital and acquired defects are primary disorders that cause secondary functional disorders, which, in turn, have a negative impact on the development of a number of psychological processes in both adults and children.

Also read the description of children with visual impairments in the material, and how to obtain a visual disability at the link.