Retinal detachment or what makes people blind? By whom and how is blindness diagnosed? Blindness and low vision What type of vision causes blindness?

11.09.2014 | Viewed by: 5,269 people

Blindness is the main problem in ophthalmology and the leading cause of disability in humans.

Currently, approximately 100 million people in the world are blind, and their number is constantly growing.

This is due to the irrational organization of safety in working conditions, at home, and violation of the rules of use. toxic substances in industry, agriculture, with a bad environment.

Types of blindness

Blindness is classified into several types.

According to the degree of decline in visual acuity, it is:

1. Complete or absolute. The patient sees absolutely nothing.
2. Subject. A person does not see the outlines of objects that are around him, but visualizes the light source and its intensity.
3. Incomplete, or civil. The patient cannot count the number of fingers if he looks from a distance of 3 meters. This fact prevents him from working and reduces his ability to self-care. Patients cannot live alone and constantly need help. This type of blindness is often called everyday blindness.
4. Professional. Blindness does not allow a person to fulfill his professional duties, but he is quite capable of caring for himself in everyday life.

The causes of blindness may be:

1. Congenital. This disease is a consequence of genetic disorders, including hereditary cataracts, retinal aplasia, tumors of the eye and orbit, and taperetinal degenerative processes. In addition, congenital blindness develops against the background of an adverse effect on the fetus during pregnancy, for example, when the mother suffered from syphilis, rubella, toxoplasmosis, was poisoned by drugs, poisons, etc.
2. Acquired. Becomes a consequence of influence various factors- for the fetus during childbirth, or in early period after birth. Retinopathy of prematurity and hypoxia during childbirth can lead to blindness. In adults, the cause of acquired blindness is eye injury, systemic diseases, pathologies of the heart and blood vessels, metabolic disorders, previous infections, many diseases of the central nervous system, including infectious ones.

According to WHO classification, blindness can be:

1. Category one— visual acuity 0.1-0.3 (low vision).
2. Category two- 0.05-0.1 (low vision).
3. Category three- 0.02-0.05 (blindness).
4. Category four- at the level of sensation of light (blindness).
5. Heel category I have no light perception (total blindness).

In terms of visual fields, the third category includes those patients whose indicator is 5-10 degrees around the point of fixation.

The fourth category includes patients with visual fields of less than 5 degrees. In addition, to evaluate the results of measures against blindness, there is a special indicator - the number of blind people per 10,000 population.

The level of measures to combat the disease in the country is poor - more than 20 people, satisfactory - 10, good - 6 or less.

Statistics show that vision problems occur in almost every third resident of the country. Every year about fifty thousand people become disabled for this reason. The causes of the disease are varied. More often these can be infections and inflammatory processes, visual impairment and eye injuries.

Temporary vision loss can occur suddenly or go away instantly

Short-term loss of vision is an ailment characterized by the inability to see any individual objects, their shade or shape. The problem may appear unexpectedly, but it also goes away instantly.

In some cases, a person develops selective blindness when only a certain area of ​​\u200b\u200bvisibility disappears. In this case main reason The development of blindness is a disorder of a specific part of the brain.

As a rule, the disease mainly affects one eye, but it can affect both at once. After the problem disappears, it may return again, but this time affecting the second organ of vision.

Most often this occurs in elderly people who suffer from any vascular disease, especially problems of cardio-vascular system.

On average, the duration of vision loss does not exceed several hours. In addition to loss of vision, a person experiences the following symptoms:

• Pain in the affected eye
• Fear of bright light
• Severe pain eyeball
• Eye squeezing

In addition, with temporary blindness, a feeling of nausea and vomiting, general weakness of the body and severe dizziness may occur. Whenever of this disease, you need to immediately contact a specialized doctor - an ophthalmologist.

Causes of temporary blindness

Intracranial pressure may be a cause short-term loss vision

There are many factors that provoke the development of short-term blindness. But experts identify a number of reasons that are the most common. The disease can develop when:

• Thrombosis of spinal vessels
• Intracranial pressure (hypertension)
• Acute glaucoma
• Diabetes mellitus
• Optic neuritis
• Retinal detachment
• Functional disorders
• Neovascular macular degeneration

In addition to the above reasons, there are others that relate to diseases of the cardiovascular system.

If in a person, then with a sharp and regular increase pressure, he may experience temporary blindness. This happens due to the fact that pressure causes disturbances in the normal blood circulation through the vessels of the eyes.

At hypertensive crisis Short-term vision loss may also develop. First, a person gets goosebumps before his eyes, dark spots or flashes, and only then he completely loses the ability to see with one or two organs of vision at once.

Loss of visibility may occur, lasting up to three hours. After this time, vision returns again.

For more information about some of the causes of temporary blindness, watch this video:

Diagnosis of short-term vision loss

Only a specialist can determine the real cause of temporary blindness.

To treat temporary blindness, it is necessary to undergo diagnostics. There are medical sites where, after going through special test, you can find out why the disease arose and how to treat it correctly.

But self-diagnosis does not exclude the fact that the patient urgently needs to see a doctor. Only a specialist can accurately determine all the details and features of this phenomenon.

To undergo diagnostics, you need to visit an ophthalmologist's office. It includes the following procedures:

• Visual inspection
• Analysis of urine
• General blood analysis
• Biomicroscopy
• Examination of the nerves and blood vessels of the affected eye

According to the results diagnostic procedures The doctor will be able to choose the right treatment.

Treatment of short-term blindness

In case of temporary blindness, the doctor prescribes special restorative vitamins

First of all, treatment of temporary vision loss is aimed at eliminating the cause that provoked the development of the disease.

Most often, with short-term blindness, the patient is prescribed special restoratives. These include:

1. Ascorbic acid. The drug contains vitamin C, which promotes collagen synthesis, regeneration of affected tissues and blood clotting.
2. Retinol. This product contains vitamin A, which affects cell reproduction and growth.
3. Thiamine. Main active substance is vitamin B1, which helps normalize eye pressure.
4. Tocopherol. The medicine has the ability to prevent retinal detachment. Active ingredient The drug is vitamin E.

In addition to vitamins, the doctor may prescribe special eye lotions based on beneficial substances and herbs.

It also offers treatment for temporary loss of visibility using various medicinal plants, which are used in the form of solutions, infusions, decoctions, compresses and baths.

To ensure your vision always remains good, you need to visit an eye doctor several times a year.

If the disease takes you by surprise, it is better not to wait for it to go away on its own. If you do not consult a doctor in a timely manner, complications may develop, including complete loss of vision. In addition, as mentioned above, short-term blindness in most cases is only a symptom of a serious and dangerous disease.

In ophthalmology there are different types blindness - from complete loss of vision to partial. Depending on the causes of vision impairment, both eyes or just one of them may be affected. Human vision is the main sensory organ through which information from the outside world is received, and its loss negatively affects the quality of life and work activity.

Partial or complete blindness is not only associated with biological pathologies, but also depends on the safety of the workplace, home environment, and the presence of contact with chemical and toxic substances. Polluted environment, pesticides in agriculture or insufficient intake ingestion of microelements can lead to partial or complete blindness.

What is visual acuity, what are the deviations?

Visual acuity is the ability of the eye to distinguish between two figures that are close to each other. When checking, Sivtsev-Golovin tables are used, consisting of 12 rows. The top line in these tables is for people with normal vision visible at 50 m, and a tenth at 5 m. This vision is designated 1.0. Additional lines (11-12) are visible to people with above-normal vision, 1.5 and 2.0, respectively, but this is not the limit: there is evidence of people who are able to distinguish faces at a distance of 1.5 km.

Even a person with perfect vision can go blind, this is due to for various reasons, both congenital and acquired. WHO recommends undergoing preventive examination 1 time per year. Timely diagnosis is necessary to prevent vision loss. Around the world, 300 million people suffer from this disease. In ophthalmology, blindness refers to vision anomalies in which a person completely or partially loses visual perception.

Pathologies causing deterioration or loss of vision:

1. Eye cancer.
2. Cataracts, clouding of the lens in old age.
3. Eyeball injury or cerebral hemorrhage.
4. Glaucoma due to high blood pressure.
5. Weakened vision due to HIV or CMV infection.
6. Retinoblastoma, a common form of childhood cancer.
7. Retinopathy caused by diabetes.
8. Amblyopia. With it, blindness in one eye occurs when the brain suppresses the functioning of the organ to obtain a clear picture.
9. Strabismus.
10. Infectious diseases that can cause complications on the sensory organs.
11. Inherited diseases that cause decreased vision.
12. The cause of blindness is an anomaly in the refraction of light rays.

The occurrence of the latter factor can cause:

1. Myopia. The focal point of light rays is not on the retina, but in front of it, which makes it difficult to see distant objects.
2. Farsightedness. The focal point is located behind the retina, and only with age-related farsightedness are distant objects clearly visible.
3. Astigmatism. Violation of the shape of the lens or eyeball, due to which objects blurred boundaries or they are forked.

So that the doctor can put correct diagnosis, you need to undergo a comprehensive examination.

Blindness can be either congenital or acquired. Congenital blindness occurs when hereditary diseases, intrauterine defects in fetal development, poisoning or infections suffered by the mother during pregnancy. It is placed immediately after birth. Acquired blindness occurs when oxygen starvation And birth injuries, immune diseases, diabetes, pathologies affecting the central nervous system, including infectious diseases, diseases of the cardiovascular system, injuries, poisoning with toxic substances and poor nutrition.

Types of blindness

Blindness can be permanent, when irreversible changes have occurred in vision, and temporary, when the loss of senses is episodic. There are many classifications of blindness, the main ones being: according to the degree of vision loss, and the cause of its occurrence. To determine the disease, visual acuity is determined, intraocular pressure and field of view separately for each eye.

Classification according to the degree of visual impairment contains the following concepts:

1. Occupational blindness. If you lose your vision, it is impossible to continue your professional activities.
2. Partial blindness. It is impossible to clearly see an object located at a distance of 3 m or count the number of objects at this distance.
3. Subject or practical blindness. There is light perception, the outlines of objects are indistinguishable.
4. Absolute blindness. There are no visual signals, the pupil does not respond to bright light. The optic nerve does not convey the characteristics of objects, their color, size, or distance to them.

Visually impaired:

• first category - 10-30% of the norm, with one eye, with correction with glasses;
• second category - 5-10% of the norm, with one eye.

• third category - 2-5% of the norm;
• fourth category - only the sensation of light is present;
• fifth category - there is no light perception, patients do not see anything.

Due to their occurrence, the following conditions are distinguished:

Signs of vision problems

Vision - difficult process. Due to the fact that a person has 2 eyes, the world appears not flat, but voluminous. From the advantage binocular vision a deficiency occurs when the patient notices with one eye. Without proper testing, signs may not be noticed for several years. Not regularly visiting an ophthalmologist is a dangerous practice that exposes the main channel of information to unnecessary risk.

Reasons for urgently visiting a doctor:

• discharge from one or both eyes;
• persistent tension in the muscles surrounding the eyeball, regardless of the degree of fatigue;
• nervous tic in a calm emotional state, lasting for 1 week;
• pain in the eyelids or eyeballs that does not go away within 3 days;
• constant drying of the eyeballs, which may indicate problems with blood supply or a fungal infection;
• sensation of a foreign object that did not go away after washing the eye;
• pain or pressure in the back of the eyeball, often a warning sign of a stroke;
• frequent cases of burst vessels, which indicates increased intraocular pressure.

When going to the doctor, not only visual acuity is measured, but also horizontal and vertical viewing angles, as well as intraocular pressure. These checks will allow you to notice deterioration before degeneration becomes irreversible. Children need additional preparation for the examination.

Consequences of blindness

At significant reduction vision, patients feel distanced from the world, problems arise with orientation in space, it becomes impossible to recognize Exact size or distance to an object. A decrease or cessation of labor activity leads to a deterioration in living conditions. With such a vast increase in negative situations, people experience negative emotions, depression, thoughts about the wrongness of life and suicide attempts. When examining and deciding on the degree of blindness, a special scale is used.

Blind people include:

• completely lost vision;
• people who only have light perception left;
• patients who have residual vision of 0.02-0.05 from normal.

A blind patient needs psychological help, in order to cope with emotional stress. Only the help of doctors specializing in vision loss will make it clear to the patient how to prepare for changed circumstances.

When the emotional background returns to normal, the brain redistributes resources between other senses, which take on the functions of lost vision. The sense of hearing, smell and touch is enhanced, resulting in improved orientation and long-term memory. Analytical abilities increase logical thinking and attention, thanks to which blind people can navigate in space. An important component of further existence is the memory of visual images of various objects.

At timely diagnosis four out of five people with blindness could have avoided it. To detect a problem in a timely manner, you must undergo annual examination see an ophthalmologist to see if the necessary nutrients are supplied with your diet. It is also necessary to monitor personal safety and avoid toxic effects on the body. In ophthalmology, dysfunctions are considered irreversible optic nerve or cerebral hemorrhage, all other diseases are treated with to varying degrees success.

People who are at risk with a predisposition to pathologies when there is visual impairment (blindness can develop unnoticed), as well as those who have suffered injury to the eyes or occipital lobes of the brain, must undergo annual diagnostics and consult a doctor if symptoms of visual impairment are detected.

Video

This term has other meanings, see Blindness (meanings).

Blindness - medical term, implying complete absence vision or his serious damage. There are complete blindness ( amaurosis) And partial loss field of view ( scotoma) or half fields of view ( hemianopsia). In addition, color blindness is distinguished ( colorblindness).

WHO definition

The tenth revision of the Statistical Classification of Injuries, Diseases and Causes of Death published by WHO defines partial vision as vision less than 6/18 but greater than 3/60, or a narrowing of the visual field of up to 20 degrees. Blindness is the ability to see less than 3/60 or a narrowing of the field of vision to 10 degrees.

Causes of blindness

World Health Organization among common reasons of blindness indicates the following (in parentheses the proportion of cases of blindness is indicated), three quarters of all cases of blindness can be prevented or treated:

• cataract (47.9%)
• glaucoma (12.3%)
• Decreased vision associated with aging (8.7%)
• corneal opacity (5.1%)
• diabetic retinopathy (4.8%)
• blindness in children (caused in particular by vitamin A deficiency, cataracts and retinopathy of prematurity (ROP)) (3.9%)
• trachoma (3.6%)
• onchocerciasis (0.8%)

Among others, blindness can also be caused by traumatic eye injuries and infections (for example, blenorrhea, syphilis, etc.). Blindness that develops with age and also caused by uncontrolled diabetes is becoming increasingly common around the world. On the other hand, as a result of health action, the number of cases of blindness due to infection is reduced. Thus, the number of people suffering from trachoma, which leads to blindness, decreased from 360 million in 1985 to 40 million in the early 2000s.

Developing countries

Blindness is present on a much larger scale in the developing countries of the world than in developed countries peace. According to WHO, 90% of all blind people live in developing countries. Of these, cataracts are responsible for 65% (22 million cases). Glaucoma causes blindness in 6 million cases per year, while onchocerciasis is responsible for approximately 1 million cases of human blindness per year worldwide.

The number of people going blind from trachoma has fallen sharply over the past 10 years, from 6.0 million to 1.3 million cases per year, making it the seventh leading cause of blindness worldwide. Xerophthalmia affects 5 million children every year; 0.5 million have corneal damage, and half of them go blind. Corneal scarring from all causes is currently the fourth leading cause of blindness in the world.

People in developing countries are significantly more likely to experience visual impairment as a result of conditions or diseases that could be treated or prevented than people in the developed world. Although vision impairment is most common among people over 60 in all regions, children in poor communities are more likely to suffer from blindness than their wealthier peers.

The link between poverty and treatable visual impairment is most evident when regional comparisons are made. Most visual impairments in adults are North America and Western Europe is associated with age-related degeneration macular spot and diabetic retinopathy.

Childhood blindness can be caused by pregnancy-related causes such as congenital rubella and retinopathy of prematurity.

Injuries

Eye injuries, most common in people under 30 years of age, are the leading cause of monocular blindness (loss of vision in one eye) throughout the United States. Damage and cataracts affect the eye itself, and developmental abnormalities such as optic nerve hypoplasia affect the nerve bundle that sends signals from the eyes to the back of the brain, which can lead to decreased visual acuity.

Cortical blindness results from damage to the occipital lobe of the brain that prevents the brain from correctly receiving or interpreting signals from the optic nerve. Symptoms of cortical blindness vary greatly among different people and may be more severe during periods of exhaustion or stress. Typically, people with cortical blindness have worse vision towards the end of the day.

Genetic defects

People with albinism often have vision loss to such an extent that many are legally blind, although few actually cannot see. Leber congenital blindness can lead to complete blindness or severe vision loss from birth or early childhood.

Recent advances in mapping the human genome have also determined other genetic reasons decreased vision or blindness. One such example is Bardet-Biedl syndrome.

Poisoning

In some cases, blindness is caused by taking certain chemical substances. Fine famous example is methanol. Methanol oxidizes to formaldehyde and formic acid, which in turn can lead to blindness, many other complications and even death. Methanol often enters the human body as an impurity when using denatured ethyl alcohol (denatured alcohol) as a drink, which is cheaper than food grade ethanol because excise taxes are not included in its price. Taking 30 milliliters of methanol can lead to irreversible optic nerve degradation caused by methanol metabolites.

Deliberate actions

Blinding in some cases was used as an act of revenge and torture to deprive a person of the main sense with which he can control the world around him, act completely independently and navigate the events taking place around him. A classic example is Oedipus the King, who blinds himself after learning that he has fulfilled a terrible prophecy. Having suppressed the Bulgarian uprising, the Byzantine Emperor Basil II the Bulgarian Slayer blinded as many as 15,000 prisoners captured in battle before releasing them.

The Old Testament law of “an eye for an eye, a tooth for a tooth,” which is also part of the Sharia, continues to be sometimes applied in our time. In 2003, a Pakistani anti-terrorism court sentenced a man to be blinded as punishment for depriving his fiancée of her sight by throwing acid in her face. The same sentence was passed in Iran in 2009 against a man who threw acid in the face of his girlfriend, and the sentence had to be carried out by the victim herself.

Forms of blindness and its severity

Various scales are used to determine blindness. Complete blindness defined as an absolute lack of reaction to light. However, in many countries the concept has been introduced practical blindness. Practical blindness (partial ability to see) is a condition when a person distinguishes between light and dark, and sometimes even has some ability to perceive visual information, but this ability is so insignificant that it has no practical significance. In the US and many European countries, practical blindness is defined as the ability to see 20/200 (that is, the patient must be 20 feet away from the object [approximately 7 meters] to observe it as well as they can healthy man from a distance of 200 feet, that is, 70 m). In many countries, a person with a visual field of less than 20 degrees (normal is 180 degrees) is also considered practically blind. Feigning blindness in healthy eyes is extremely rare and is easily recognized by appropriate control methods of vision testing. There are, however, frequent cases of exaggeration of the existing decrease in vision in the presence of a real pathology of the organ of vision.

See also Pseudo-blindness.

International classification

Main article: List of ICD-10 classes

The International Classification of Diseases, Tenth Revision, Class VII, contains section H, in particular "Visual impairment and blindness (H53-H54)".

H53-H54.7

H53-H54 - Visual disorders and blindness:

• H54.0 Blindness in both eyes
• H54.1 Blindness in one eye and reduced visual acuity in the other eye
• H54.2 Decreased visual acuity in both eyes
• H54.3 Unspecified loss of vision in both eyes
• H54.4 Blindness in one eye
• H54.5 Reduced visual acuity in one eye
• H54.6 Unspecified loss of vision in one eye
• H54.7 Unspecified vision loss

Blind people and society

Blind people are people with completely or almost completely absent vision. People are blind from birth or acquire blindness as a result of injury or illness. In case of blindness, a person becomes and is recognized as disabled. Blind people navigate in space with the help of hearing and touch, special devices, guides and guide dogs.

Public support for the blind and social rehabilitation

Education for the blind is carried out in specialized schools and boarding schools.

Blind people use Braille to read. There are special libraries for the blind, which store books in raised Braille and audiobooks on various media. The largest library for the blind in Russia is the Russian State Library for the Blind. In addition to embossed books and audiobooks, it contains large collection relief-volumetric models that allow the blind to recognize the appearance of various objects.

Organizations of the blind

• All-Russian Society of the Blind
• Ukrainian Society of the Blind (Ukrainian) Ukrainian Association of the Blind, UTOS)
• Braille League (Belgium)

Creating a Blind Friendly Environment

Traffic lights with signal duplication by sound Relief paving of streets Barriers Duplication of inscriptions in Braille Special services help

In some tourist destinations, small-scale 3D models of the environment are created for the blind, which allow them to become familiar with the surrounding architecture through the use of touch.

Modern achievements of science in the fight against blindness

Guide dogs

Main article: Guide-dog

For several hundred years, dogs have been used as guide dogs - specially trained animals that help blind and visually impaired people move outdoors and avoid obstacles.

Computer electronic devices

• Currently, an interesting alternative to printed books are audiobooks, which allow you to listen (in sections, sometimes with the option of pausing) to dramatizations and audio performances on a digital audio player. There are sites where audiobooks are created by volunteers for free distribution.
• In addition to audiobooks specially recorded by speakers, special voice screen reading programs based on a speech generator are of practical value for the blind.
• Blind people can edit texts on a personal computer using a regular or special Braille keyboard and a Braille display.
• Under development various devices, for example, the Tactile Vision Project - models of visual replacement devices - vision substitutes, "a new patented method of encoding and transmitting a signal."

Computer programs for the blind

For the use of computers by the blind, Braille and speech input and output are commonly used. In addition, tactile electromechanical panels are used to display graphic information in a tangible form.

Distributions specially developed operating system Linux for the blind - Oralux (English) and Adriane Knoppix (English). There is also computer game NetHack with an interface for the blind.

Modified data visualization including large font and simple, contrasting graphic images, convenient for people with residual vision.

There is also WAI-ARIA web technology to enable people with total or partial vision loss to use the Internet.

Bionic eye

Main article: Bionic eye

• Bionic eye- artificial visual system recovery lost vision. An implant is implanted into an eye with a damaged retina - a prosthetic retina, complementing the retina itself with the intact neurons remaining in it.

The technology differs in that a camera is built into special glasses, from which information is sent to a video processor that the patient wears on his belt. The processor converts the image into an electronic signal and sends it to a special transmitter, also built into the glasses. This transmitter then sends a wireless signal to a tiny electronic receiver built into the eye and a photosensor (electrode panel) that is implanted in the patient's retina.

The photosensor electrodes stimulate the remaining active optic nerves in the retina, sending electrical video signals to the brain through the optic nerves.

Application

• In Great Britain, a completely blind man “received his sight.” A 76-year-old patient named Ron, who became blind 30 years ago due to hereditary disease, managed to transplant the so-called bionic eye, which was invented by American scientists.
• ‎51-year-old Peter Lane in the UK was one of the first in the world in December 2009 to have electronic photo sensors implanted in his eye, sending signals to the brain collected by special glasses. This technology allowed the patient to see the outlines of objects, for example, a door, a closet, and even recognize letters for the first time in 30 years.
• In Germany (2009), an experimental 3x3 mm sensor (1500 elements) was implanted under the retina in seven patients.
• There are new methods of restoring vision to the blind using a video camera and electrodes implanted in the brain.

Other inventions and technical devices for the blind

Due to the high cost of training guide dogs, Lately electronic guides appeared, for example the Electrosonar device for the blind. Having detected an obstacle, Electrosonar emits a sound or vibration signal of different durations (the duration of the signal depends on the distance to the obstacle). By pointing the device in different directions, you can get a clear picture of surrounding obstacles, such as curbs, steps, walls. Technology is being developed to allow blind people to drive.

Scientists in Chicago are currently testing a new device, the Argus II, that will help the blind see. The device consists of an implant that is implanted into the retina of the eye and special technological glasses. The lenses of the glasses transmit the image through a video processor, which in turn sends instructions to the implant. These messages stimulate the retina to send signals along the optic nerve to the brain. This is how a person can see the outlines of objects and light contrasts. In the United States, such studies are currently being conducted in 13 places.

Some famous blind people

There are known people who, thanks to their own talents and the help of others, achieved great heights in art, science, social activities, despite their blindness or blindness from birth. Among them are Homer (8th century BC); John Milton (17th century); in the 20th century - Borges, Helen Keller, Nikolai Ostrovsky, Vanga, Eduard Asadov, Ray Charles, Stevie Wonder, Andrea Bocelli; in the 21st century - Diana Gurtskaya and Oleg Akkuratov.

Blindness in religion, mythology and art

Mention in the Bible

When “the blind man leads the blind” is a biblical parable where Christ, referring to the Pharisees, explains: “ leave them alone: ​​they are blind leaders of the blind; and if a blind man leads a blind man, both will fall into a pit."(Matt. 15:14 and Luke 6:39).

The New Testament contains numerous instances of Jesus performing miracles to heal the blind.

Mythology

The parable of the blind men and the elephant is common to many religious traditions and is part of Jain, Buddhist, Sufi and Hindu cultures. IN various options parable, a group of blind people (or those in the dark) touch an elephant to understand what it is. Each of them touches different parts of his body, but only one of them, for example, the side, trunk or tusk. They then describe their touching experiences to each other and begin an argument as each describes the elephant differently, with none of the descriptions actually being correct.

In Greek mythology, Tiresias was a soothsayer known for his clairvoyance. According to one myth, he was blinded by the gods as punishment for revealing their secrets, and another myth says that he was blinded as punishment for seeing Athena (or Artemis in another version) naked while she was bathing. Ovid suggests that he turned into a woman, then back into a man, and when he asked Zeus in which hypostasis the pleasure from sexual intercourse was greater, he answered that in the female, Hera, dissatisfied with the answer, blinded him.

In the Odyssey, the cyclops Polyphemus is deceived and blinded by Odysseus. In Norse mythology, Loki tricks the blind god Höd into killing his brother Balder, the god of happiness. One sacrifices one eye to gain wisdom.

New time and modernity

Dutch painter and engraver Rembrandt often depicted scenes from the apocryphal Book of Tobit, which tells the story of a blind patriarch who healed his son Tobias with the help of the archangel Raphael.

Matt Murdock, the Marvel Comics character known as Daredevil.

Modern fiction contains numerous examples of blind characters.

- This pathological condition, in which visual acuity is sharply reduced or completely absent. Depending on the form of the disease clinical symptoms represented by a decrease in visual acuity, the appearance of scotomas, impaired color perception, loss of the nasal or temporal halves from the visual field. Diagnosis of blindness is based on the results of visometry, perimetry, ophthalmoscopy, fluorescein angiography, electroretinography, campimetry, the Ishihara and FALANT tests, and the Rabkin table. Etiotropic therapy various forms blindness differs significantly and is selected for each patient individually.

General information

Causes of blindness

According to WHO statistics, the most common cause of blindness is cataracts (47.9%). Congenital variants of the disease are caused by mutations. As a rule, the reasons for decreased visual acuity in such cases are a familial form of lens opacification, aplasia inner shell eyeball, tapetoretinal degenerations, albinism. Special view This pathology is cortical blindness, in which clinical manifestations caused by damage to the occipital lobe of the brain. Common teratogens in relation to the organ of vision are medications, toxins and pathogens of infectious diseases.

Exists high risk eye damage due to the action of teratogenic factors on the fetus at the stage embryonic development. In the prenatal period, the development of blindness is provoked by pathogens such as rubella, toxoplasmosis, influenza, and tuberculosis. IN mature age Chlamydial origin of visual impairment due to trachoma is more often observed. Eye damage with frequent loss vision is typical for helminth infections such as onchocerciasis. Isolated cases of blindness are diagnosed with dirofilariasis.

Etiology of blindness early age associated with exposure to triggers during the birth or perinatal period. In this case, newborns are diagnosed with retinopathy, hypoplasia visual pathways or hypoxic damage to the optic nerve, which subsequently leads to visual dysfunction. In children (especially premature ones), a decrease in visual acuity is potentiated by vitamin A deficiency, congenital lens opacity or retinopathy. In patients young Most cases of monocular blindness are caused by traumatic injuries. In old age, decreased vision is associated both with general diseases of the body and with the course of degenerative changes in the retina or optic nerve.

Damage to the inner lining of the eyeball or optic nerve with a progressive decrease in visual acuity is typical for such common diseases, such as arterial hypertension, atherosclerotic vascular damage, retinopathy due to diabetes mellitus. Blindness can occur secondary to pathologies of the central nervous system– meningitis, encephalitis, toxic brain damage. According to statistics, with timely diagnosis, many cases of this pathology are potentially reversible. As a rule, the cause of irreversible blindness is glaucoma due to the development of optic nerve atrophy.

Symptoms of blindness

Clinically, blindness is classified into amaurosis, scotoma, hemianopia, and color blindness. According to the WHO, a diagnosis of blindness can be made when vision is less than 3/60 or the visual field is narrowed to 10 degrees. If visual acuity is 0, we are talking about absolute blindness. With preserved light perception and response to changes in its intensity, but the inability to distinguish the shape of surrounding objects, blindness is called object blindness. In the civil variant of visual dysfunction, the patient cannot determine the number of fingers on his hand at a distance of 3 meters. There is also occupational blindness, in which visual impairment interferes with the performance of professional duties.

A specific symptom of transient amaurosis is sudden loss vision for a total duration of no more than 10 minutes. This phenomenon is associated with reversible ischemic changes in a swimming pool carotid artery. Leber's amaurosis is manifested by nystagmus and a pronounced decrease in visual acuity, detected even in early childhood. Often this form of blindness is combined with keratoconus, cataracts, astigmatism, and strabismus. Extraocular manifestations of pathology are represented by a delay mental development, epileptic seizures, hearing loss, hormonal imbalance, kidney malformations, skeletal system or CNS. Patients with this type of blindness in rare cases are able to distinguish light from darkness or track the movement of nearby objects.

With pathological scotomas, visual field defects are detected, which the patient sees as dark spots before the eyes. These defects can partially obscure the image in question. When scotomas are detected, which the patient does not notice, we are talking about a “negative” version of the pathology caused by damage to the optical nerve fibers. Hemianopsia is binocular blindness affecting one half of the visual field. In the homonymous form of the disease, both right or left halves are lost; in the heteronymous binasal form, the lateral parts are lost; in the heteronymous bitemporal form, the medial parts of the visual field are lost. With color blindness, the ability to differentiate a specific color is impaired. Protanopia is manifested by the inability to perceive red, tritanopia – blue-violet, deuteranopia – green. Achromatopsia is a blindness characterized by pathological color perception, in which patients are unable to distinguish all shades of the color spectrum.

Diagnosis of blindness

Diagnosis of blindness is based on visometry, perimetry, ophthalmoscopy, fluorescein angiography, electroretinography, and campimetry. Visometry allows you to diagnose the degree of impairment visual functions. Category I includes patients with visual acuity of 0.1-0.3 diopters, category II – 0.05-0.1 diopters, and category III – 0.02-0.05 diopters. In category IV patients, light perception is preserved - 0.02 diopters; in category V patients there is no light perception. In accordance with the results of the examination, patients included in groups I and II are classified as visually impaired. The diagnosis of blindness can only be made to persons III-V groups. A visual field of 5-10° according to perimetry corresponds to category III, less than 5° – IV.

Also, when performing perimetry, it is possible to identify pathological scotomas, which have the appearance of visual field defects of an oval, round or arcuate shape. Using the campimetry method, the size of the scotoma is measured in the temporal, nasal, frontal and chin points and in 4 oblique meridians, followed by recording the indicators in a special patient chart. The main method for diagnosing hemianopsia is perimetry. In the homonymous form of blindness, visual field defects are found in the temporal and nasal regions different eyes. The binasal variant of the pathology is characterized by loss of the medial, and bitemporal - by the lateral halves of the visual field.

For transient amaurosis, fluorescein angiography is indicated to determine the exact location of the ischemic zone. As a rule, the study reveals embolism of the arteries of the inner lining of the eyeball. Leber amaurosis is characterized by a decrease in the amplitude of waves or their complete absence during electroretinography. During ophthalmoscopy in patients over 8 years of age, calcifications and pigment bodies are detected along the periphery of the fundus. To diagnose color blindness, the Ishihara test, Rabkin’s polychromatic tables, and the FALANT test are used.

Treatment of blindness

In case of transient amaurosis, it is urgently necessary to prescribe vasodilators, anticoagulants direct action, thrombolytics, antiplatelet agents. Specific treatment tactics for Leber blindness have not been developed. Symptomatic therapy includes taking multivitamin complexes and intraorbital injections of vasodilators, correction of visual acuity with glasses. When diagnosing scotomas, etiotropic treatment is required. If the cause of the disease is retinal detachment, vitrectomy followed by filling or ballooning of the sclera is indicated. When visual field defects appear due to pathological neoplasms, they are removed. In case of blindness caused by spasm of cerebral vessels, it is necessary to prescribe antispasmodics.

Etiotropic therapy of hemianopsia is based on stopping causal factors. Neurosurgical intervention in patients with this form of blindness is indicated for traumatic brain injury, benign or malignant brain tumors. If special treatment methods are not available, a course of rehabilitation is recommended. Specific tactics for the treatment of color blindness have not been developed. To correct visual functions, glasses with special filters or contact lenses are used.

Forecast and prevention of blindness

Specific prevention of blindness has not been developed. With timely diagnosis and treatment, in most cases, visual functions can be preserved. All patients with this pathology must be registered with an ophthalmologist. The prognosis for blindness is often unfavorable. 95% of patients with Leber amaurosis lose their vision irreversibly by age 10 years or earlier. However, with color blindness, visual acuity often does not change. Decreased visual function can cause temporary or permanent loss of performance. If it is impossible to restore the functions of the organ of vision, patients are assigned a disability group. When visual acuity is 0.05-0.2 diopters, it is recommended to study in a special school for visually impaired children, below 0.05 diopters - in educational institutions for the blind.