How to cure color blindness: is it possible to cure the disease at home?

Visual impairment can be of various types, such as color blindness. Difficulty in distinguishing colors is called color blindness. In Russia, 4% of the population is color blind, that's about 5 million people. There are 200 million colorblind people in the world. For some people, this problem is insignificant and does not interfere with their choice of profession, in life, etc. For others, colorblindness becomes a serious obstacle, because it prevents them from doing their intended activities. Naturally, such people want to know about this phenomenon and methods of leveling it.

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Color blindness - what is this disease?

Color blindness, or color blindness, is a visual impairment, namely the function of color perception. With this pathology, a person does not distinguish between one or more colors. Cones, photoreceptors located in the macula, the central part of the retina, are responsible for their perception in the eyeball. There are 3 types of cones, each containing red, blue or yellow protein pigments. Actually, these are the main shades, the mixing of which forms many other tones. In the absence of one or more pigments, color perception is impaired.

Signs

The pathology is characterized by only one symptom: impaired color perception by the retina, while visual function does not suffer at all, and there is no pain. In early childhood, the problem is rarely detected, which is associated with the “laying in” of certain attitudes from adults (the sky is blue, the grass is green, etc.). Parents may only become concerned if the child is unable to distinguish red or green from gray.

The retina of a healthy eye normally recognizes the basic tones - red, blue, yellow. The retina of a colorblind person may not recognize shades at all (achromasia), contemplating the surroundings in a gray palette, not perceive one of the pigments (dichromacy), or poorly distinguish between pigments (abnormal trichromancy).

For the first time, color vision disorders were described in detail by the English naturalist and self-taught teacher D. Dalton, in whose honor the pathology later received its name.

If you see poorly at a distance, read myopia and how to restore vision.

Definition

Read the instructions for eye drops at the link.

Why does color blindness occur?

Congenital color blindness, which is diagnosed in most cases, is inherited. The transmission of the color blindness gene is associated with the X chromosome, the carrier of which is the mother. She can pass this gene on to her child while remaining healthy.

Acquired color blindness develops with eye injuries, as well as pathologies of the visual organs and the central nervous system with damage to the optic nerve. Color blindness is not an independent disease. Thus, with cataracts, characterized by clouding of the lens, light does not penetrate well through the structures of the optical system of the eyeball, as a result of which the ability of photoreceptors to perceive colors is impaired. When the optic nerve is damaged, all functions of the eye responsible for vision deteriorate. Color perception is also impaired, although the condition of the cones may be normal. Failures in the transmission of nerve impulses to photoreceptors can also occur in diseases such as Parkinson's disease, cancer, and stroke.

Sometimes color blindness is a side effect of certain medications, but it doesn't happen very often. Color blindness can affect one or both eyes, with varying degrees of damage to the photoreceptors in each. If you are color blind, one eye can perceive colors better than the other.

Treatment of color blindness

The acquired form of color blindness can be eliminated depending on the cause of the disease. So, if problems in color discrimination are a consequence of cataracts, then surgery to remove them can improve color vision. If this problem appears due to taking medications, color vision can be restored by stopping treatment.

Genetic color blindness cannot be cured.

People suffering from a mild form of color blindness - dichromia - learn to associate colors with specific objects and in everyday life are often able to identify colors, just like people with normal color perception, although their perception of colors is different from normal.

Several years ago, successful results of correcting color blindness in monkeys using genetic engineering methods were published. The essence of the method is to introduce missing genes into the retina. However, such experiments have not been carried out on humans.

There are also methods for correcting color blindness using special lenses. Recently, special glasses with lilac lenses were introduced to distinguish between green and red, helping to improve the vision of people with a form of color blindness.

Clinical classification of color blindness by color

As noted, color blindness develops unevenly. This disease can take different forms. Depending on the absence of certain photoreceptors, the perception of certain shades is impaired. Normal color perception is called trichromatic when in a person, a trichromat, all three types of protein pigment function in the macula. There are three types of color blindness:

Achromasia is an absolute inability to distinguish colors. The only shade that a person sees is gray. This form of pathology is extremely rare. Monochromasia is color blindness in which only one color is perceived. As medical practice shows, this disease is accompanied by photophobia and nystagmus. Dichromasia is a type of color blindness that is characterized by the ability to distinguish only two spectrums of colors. This form of color blindness is divided into subtypes:

Protanopia is a disorder in the perception of the color red. Usually the patient confuses this shade with brown or dark green, green is perceived as light gray, and yellow as light brown.
Deuteranopia is the inability to distinguish green from other colors. It mixes with orange and yellow, and red is seen as light green or light brown. Pathology is diagnosed in only 1% of patients with color blindness.
Tritanopia is the absence of blue and violet shades in the human perceived color spectrum. The patient sees almost everything in green or red tones. As a rule, with tritanopia there is poor twilight vision.

Causes of color blindness

Most often, this is a congenital feature, due to the fact that the color-sensitive receptors on the retina - cones - are damaged. They contain their own type of pigment - red, green, blue. If there is a sufficient amount of pigment, then a person’s color perception is normal. If there is a lack of it, then one or another type of color blindness occurs, depending on which pigment is missing.

Color blindness can be congenital or acquired.

Congenital is transmitted through the maternal line through the X chromosome. In women, a damaged one X chromosome can be compensated by an intact second one, but in men there is no such compensatory possibility. Therefore, this feature occurs more often in them than in women. In women, color blindness can occur if the father has it, and the mother is a carrier of the mutated gene. It can also be transmitted to the child

According to statistics, one or another type of color blindness exists in every tenth man and in 3-4 women out of 1000.

Acquired occurs due to age-related changes, taking certain medications, or due to trauma to the retina or optic nerve, or a burn of the retina by ultraviolet radiation. It occurs in women and men approximately equally. With this type, people most often have difficulty perceiving yellow and blue colors.

How does color blindness manifest itself?

Visual acuity does not suffer with color blindness, so it is impossible to diagnose it using this parameter. Actually, this pathology may not appear for several years if we are talking about its congenital form. It is possible to identify color blindness in a child only when he stops associating each color with a specific object. For a child in childhood, the Christmas tree may be green and the sky blue. The baby does not project this information onto other objects and does not complain to parents about color vision impairment, even if it exists.

Parents may accidentally notice this in their child by noticing mistakes when naming colors. However, the first vision test, including color vision, is carried out in kindergarten. During the examination, the ophthalmologist should notice signs of color blindness.

Acquired color blindness is identified by a number of symptoms, many of which are subjective. A person may contact an ophthalmologist with complaints about:

inability to distinguish colors;
impaired perception of one, two or three primary colors of the spectrum;
photophobia, which is accompanied by lacrimation and pain in the eyes;
twitching of the eyes, which indicates the development of nystagmus.

Diagnostics

Colorblindness is often discovered almost by accident during examinations by an ophthalmologist. For this purpose, special tables and tests are used that help identify the degree of color blindness and its type - pseudo-isochromatic tables of Stilling, Ishihara, Schaaf, Fletcher-Gambling, Rabkin. The most common self-test methods are based on the properties of color and represent many circles slightly different in color and saturation. In the table, using these circles, numbers, geometric shapes, letters, etc. are encrypted. Only a person with normal color perception can distinguish them. People with pathology will see in these tables other encrypted signs that are inaccessible to ordinary vision.

However, the quality and objectivity of the test can be influenced by many factors - age, eye fatigue, lighting in the room, and the general condition of the subject. And although these tables are quite reliable, if necessary, a more in-depth check is needed, for example, using a special device - an anomaloscope. During this test, a person is asked to select colors located in different fields of vision.

Colorblind children

It is very important to diagnose color blindness in children - and as early as possible. Due to this feature of vision, the child does not receive all the necessary information about the world around him, and this negatively affects their development. Another difficulty lies in the fact that children under 3-4 years old cannot consciously name colors, and they need to be taught to correctly identify them before this age. Therefore, you need to watch the kids - mainly how they draw. And if a child constantly makes mistakes in drawing familiar objects of nature - for example, he draws grass in red and the sun in blue, this is a reason to suspect that he is color blind. True, confirmation of this may take several years.

How is color blindness diagnosed?

The ophthalmologist prescribes a polychromatic test using Rabkin tables to check color vision. This test consists of 27 main and several additional pictures, which depict geometric shapes, numbers, numbers and other symbols, colored in different tones. Perhaps every person who has been examined by an ophthalmologist remembers such pictures. The symbols on them consist of many small circles of different shades, the background is also made up of these multi-colored circles.

The doctor shows the card to the patient, who must name the symbol shown in the picture. The subject is given no more than 5 seconds to think. 27 cards are used to identify color blindness and its type. An additional two dozen pictures allow you to determine the degree of development of the pathology. Also, thanks to polychromatic tables, you can find out the causes of the disease.

In addition to the Rabkin test, the Ishihara test is used to diagnose color blindness. It is only suitable for patients who can read. Sometimes color blindness develops with mental retardation. The Ishihara test is contraindicated in such patients. To pass it you need to be able to read and understand what you are reading. The test is a letter written in red spots.

How is the color vision test performed?

In order for the test results to be accurate, the following conditions must be met:

vision is checked for color blindness in natural light;
The cards should not be exposed to direct sunlight, and they should not blind the patient;
the person being tested must feel well; if he is sick or unwell, the test results will be unreliable;
the tables are located at a distance of one meter from the patient, right at eye level;
The picture is shown for no more than 5 seconds. This time is enough for a healthy person to look at the symbol on the card.

If a person is completely healthy, he will correctly name more than 90% of the symbols. With color blindness, the patient gives no more than 25% correct answers.

Diagnostic methods

One of the most well-known methods for diagnosing color blindness remains Rabkin’s polychromatic tables, a test for color perception. The tables contain multi-colored circles of equal brightness. Various numbers and geometric shapes are made from circles of the same shade in the images. By the number and color of figures identified by a person, one can judge the degree and type of color blindness.

Rabkin table

You can also use the simpler tables of Stilling, Yustova and Ishihara. They were obtained by calculation and not by experiment. Doctors use the Holmgren method. According to it, it is necessary to sort skeins of multi-colored wool threads into three main colors.

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Is it possible to cure color blindness?

If color blindness develops against the background of any acquired pathology, for example, cataracts, then the underlying disease is treated. Its complete cure normalizes color perception.

As for hereditary color blindness, there is no cure for it today. There are attempts to introduce viral particles into the abnormal gene that would change it. Such technologies are currently at the development stage. They are not used on humans.

However, color blindness, due to which a person cannot distinguish almost any colors, is rare. In most cases, a colorblind person can see normally, limited to those spectra that are available to him. This does not cause much discomfort in life. It all depends on the type of color blindness and its degree.

Treatment

There are no methods for treating or correcting congenital color blindness yet. Acquired color blindness can be eliminated by treating underlying pathologies.

Attempts to compensate for color blindness with tinted contact lenses or glasses with tinted lenses have not been successful because they do not take into account the psychophysiology of color perception and simply color the images.

In addition, it is often necessary to turn one color into another, which is in a different spectrum (for example, pink into blue), which cannot be done using a filter.

Advances in electronics have made it possible to create corrective glasses with miniature video cameras, computer image processing and displaying it on LCD eyepieces. Such a device is quite bulky today, but further developments are underway to make it a normal size.

Colorblind people themselves can still take independent measures that would help them compensate for their defect, for example, wearing glasses with shields on the sides or wide frames. They produce less glare and are easier for colorblind people to distinguish colors, making these glasses useful.

Important! There have been recorded cases of complete cure of color blindness by experiments on animals.

American scientists injected two monkeys into the retina of the eye with a harmless virus that included the missing photosensitive receptor gene. Health was not affected, but color sensitivity was restored. This has not yet been tested in humans.

Definition of disease

In modern medicine, color blindness is considered a pathology of color perception and a violation of the basic functions of color discrimination . Colorblind people often cannot tell the difference between several shades. It is believed that the disease is directly related only to males, but women can be carriers of the abnormal gene. In addition, it may be hereditary or acquired.

Most often, colorblind people do not identify green, red and blue-violet colors. However, there are also cases when they cannot distinguish between several colors or are unable to identify any at all.

Is it possible to get color blindness?

The main reason for the inability to distinguish colors is a genetic factor. But this is not the only circumstance under which a person can develop a condition such as color blindness. The pathology can be acquired. Problems with color perception sometimes occur due to traumatic brain injuries. If the retina of the eye is affected, then it stops producing the pigment “responsible” for distinguishing colors. It happens that acquired color blindness develops in only one eye. Men and women can face this problem. The development of acquired color blindness is often preceded by certain diseases. Among them are cataracts, glaucoma, atherosclerosis, neurasthenia, and jaundice. The inability to perceive colors, which arose against the background of another disease, often leads to the development of myopia and degenerative lesions of the retina.

Treatment of acquired color blindness is quite possible. To return color perception to normal, it is necessary to eliminate the root cause of the primary disease that led to such consequences.

History of the discovery of the disease

How is color blindness transmitted?
Source: teinsmed.ru John Dalton was the first person to describe the phenomenon of reduced color vision, which forces some people to perceive the colors of the surrounding world in a completely different palette, which, however, does not really interfere with their daily activities.

For example, Dalton himself, despite his deviation, which prevented him from perceiving shades of red, lived a rather long life, dying at the venerable age of 78.

As is commonly believed, in 1794, this English chemist was the first to quite accurately describe the phenomenon of color blindness, which, in addition to him, also affected two of his siblings. Thanks to his work, in which he described his perception of the world around him, such visual anomalies were united under one general term “color blindness”, which has been successfully used for more than two hundred years.

Inheritance mechanism

Color blindness in humans is a damaged mechanism for reproducing the color image of vision. In most cases, color blindness is inherited, from the maternal side to the son. The mother perceives colors normally, but passes on the damaged X chromosome gene through the male line.

Men are 20 times more likely than women to suffer from the disease. The reason is the presence in males of one X chromosome received from the mother. Girls who have two X chromosomes are rarely color blind.

The mother's unhealthy X chromosome is replaced in the daughter by another X chromosome. The damaged gene can be passed on from the father to the girl, who becomes its carrier and passes it on to her sons. Daughters suffer from color blindness if the father and mother suffer from color blindness.

The retina of the organ of vision has nerve cells that are located in. Cell pigments sense blue, red and green. People see the surrounding reality with various shades by mixing the three main colors.

The absence of one of them leads to a violation of tone perception. The hereditary disorder affects both organs of vision. There is a problematic vision of tones acquired as a result of injuries, cataracts, weakened vision, and other factors.

The vast majority of cases of color blindness are the result of inheritance. As already noted, in most cases, color blindness is inherited, and only in some cases can it be acquired during life.

A congenital eye disorder occurs due to the fact that pathological genes are passed on during the conception of a child, which in turn cause the disorder after birth. To diagnose color blindness, special polychromatic tables are used.

Cases in which women suffered from hereditary color blindness have not been recorded. Women are carriers of a gene with pathological hereditary information, but they themselves do not suffer from such visual impairment.

Therefore, if a boy is born, the pathological gene will develop in his body. When a female child is born, the likelihood of the disease being inherited is excluded. In view of this, we can conclude that the heredity of color blindness is directly influenced by the gender of the child and the presence of pathological genes in the parents.

In this matter, the problem of color blindness among children is very acute. This is due to the fact that, due to its physiological characteristics, a child does not perceive most colors until the age of three.

Only after crossing the age threshold of three years, color discrimination gradually begins. In turn, only then can it be determined whether the child is hereditary color blind.

It is also worth noting that in cases where color blindness is inherited, people with such a disorder cannot distinguish a certain color. However, their eyes are more sensitive to other colors and shades, resulting in a color spectrum that can exceed that of even a healthy person.

Another distinctive feature of hereditary color blindness is that the disease does not cause any changes in the condition of the eyes. With acquired visual impairment, various pathological changes often occur, such as decreased visual acuity, the appearance of cataracts, and others.

In general, color blindness is a common vision disorder that involves the eye's inability to distinguish certain shades and colors. This disorder can be either congenital or acquired and requires careful diagnosis and treatment.

Colorblindness test

The presence of color non-perception is determined using the tables of Stilling, Schaaf, Rabkin and others. The main test for color blindness is the Rabkin method. It is carried out as follows: the person being diagnosed looks at two tables, which are filled with circles of the same brightness, but different colors. And he tries to make out the numbers, letters or even shapes made up of them. If a person’s color perception is fine, then he can distinguish everything that is depicted in circles in the tables. But those who suffer from color blindness cannot distinguish the figures.

If the person being diagnosed is a child, this method will not suit him, because he may not yet know either numbers or letters. Therefore, color blindness is determined in other, indirect ways. For example, they offer him several items to choose from, among which he gives preference to gray, dim things. Or a child paints the grass red. All these factors together may indicate that he has color blindness. Drivers are required to undergo a color blindness test regularly.

How does the problem arise?

In the center of the human retina there are receptors that are sensitive to color perception. Each nerve cell contains pigments - chlorolab, rhodopsin, erythrolab. With normal vision and color perception, the child has all the listed pigments in the required quantities in the receptors.

Color blindness occurs when there is a lack or absence of any color pigment. Most often, color blindness in children is associated with problems recognizing red pigment. Color blindness is a disease that results in the inability to distinguish one or more colors.

Often, the disease is transmitted genetically - from parents to child. Men are more prone to color blindness than women. Types of color blindness:

dichromia - inability to distinguish between green and blue shades;
deutanopia – inability to distinguish green colors;
violation of red receptors (most common) - a person does not distinguish between red and green colors;
lack of color vision (rare) - a person recognizes only black, gray and white shades.

The disease often does not make itself felt for a long time and can be diagnosed in adulthood. The central part of our retina has color-sensitive receptors, which are nerve cells, these are rods and cones.

These receptors, in turn, have several types of color-sensitive pigments. Chlorolab is considered as one of the pigments included in iodopsin, and erythrolab is considered as the second.

Cones themselves contain a visual pigment such as iodopsin, which consists of two pigments, both of which are sensitive to all visible regions of the spectrum.

Chlorolab has maximum sensitivity to the region of the spectrum to which the yellow-green part belongs, erythrolab, in turn, has maximum sensitivity to the yellow-red region of the spectrum.

The rods also contain a pigment such as rhodopsin. It is characterized by a specific absorption spectrum, the presence of opsin and chromophore properties, as well as the chemical bond provided between them.

There are two maximum points in this spectrum, one of them falls on the blue region (almost before reaching the ultraviolet region, reaching the limit at the point of 278 nm), it is caused by opsin, the other is the region reaching a point within 500 nm, corresponding extremely low light conditions (“twilight vision”).

Children's color blindness

Children's color blindness carries a great danger. The child may be developmentally delayed. A vision test for color blindness is only possible when the child begins to name colors or at least images.

It is quite difficult to identify the disease in a young child, since children begin to name colors only from the age of 3-4, and in order to influence color blindness, it is necessary to recognize it much earlier, before the child has yet formed the wrong idea about colors.

This can be done using drawings. When offering your child different pencils, you need to see what colors he uses to draw the sky, water, grass, sun, and so on.

By placing two toys in front of your child (one of a dull color and the other of a bright color) and observing his choice, you can also diagnose color blindness. It is more likely that a healthy baby will choose a bright toy, and a sick one, not seeing the difference, will take the first one he comes across.

In diagnosis, doctors use a series of special pictures made up of many colored dots. Only a person who can distinguish colors correctly can see what is depicted there. Problems associated with color blindness:

difficulties in choosing clothes;
reading color maps, charts and diagrams;
difficulties when driving a car (not recognizing the colors of traffic lights);
difficulties with choosing a profession.

Unfortunately, color blindness cannot be cured. Therefore, parents of colorblind children should be patient. The kid needs to know that, no matter what, he is normal, even special.

You should not focus the child’s attention on this problem, as this will not provide any benefit, and may also cause a decrease in self-esteem and withdrawal.

It is definitely worth warning your child’s teachers about the presence of this disease, since otherwise it may affect grades and provoke misunderstandings between the student and the teacher, and classmates.

A child diagnosed with color blindness simply needs support. The disease brings with it many life difficulties. Only close people can learn to overcome them.

Signs of color blindness

The disease can greatly reduce the patient's quality of life. The child may have problems with learning, and his choice of profession may be limited. But still, clarity and clarity of vision helps patients compensate for their deficiency. As a person gets older, the signs of colorblindness may change, so he may begin to distinguish some colors, or, on the contrary, stops seeing other shades.

Most often, those suffering from color blindness cannot distinguish between green, blue, and red. If the visual impairment is not too severe, then problems may arise only with the perception of blue and yellow.

If the pathology is serious, then patients with color blindness generally see the world in black and white, distinguishing only shades of gray and white.

With hereditary color blindness, there is usually trouble with color perception in both eyes. If the disease is acquired during life, then only one organ of vision may be affected. In some patients, one eye does not see more colors than the other. Hereditary color blindness develops immediately after birth and remains unchanged throughout life. The acquired disease can alleviate the course or be expressed by more severe visual defects against the background of aging of the body or other ophthalmological and systemic diseases.

Types of color vision disorders

Depending on how many pigments are missing, and, accordingly, how many shades the eye perceives, people are divided into the following color perception groups:

trichromats: normal functioning of all three cones, sufficient protein pigments, a person can distinguish all colors;
dichromats: one of the sensors does not work, there is a lack of protein pigments in the cone, so such people do not distinguish all colors;
monochromats: owners of such vision see the world around them in black and white, since only one type of cones works for them (such people do not know about other colors, since they have never distinguished them).

John Dalton, after whose name color blindness is named, discovered dichromasia. He was the first to describe the deviation from a scientific point of view.

Monochromats are the rarest group; these are people with absolute color blindness. For them, the entire world around them is black and white and shades of gray. Their eyes are easily blinded, and therefore, in daylight, they cannot distinguish shapes well, which often leads to photophobia, that is, fear of light.

The impact of color blindness on a person's life and career

Color blindness can limit a person's ability to perform certain professional skills. The vision of drivers, sailors and pilots is carefully examined, since the lives of many people depend on its correctness.

Color vision deficiency first came to public attention in 1875, when a train crash occurred in Sweden, near the city of Lagerlund, causing great casualties. It turned out that the driver did not distinguish the color red, and the development of transport at that time led to the widespread use of color signaling.

This disaster led to the fact that when hiring for a job in the transport service, it became mandatory to evaluate color perception. And now, if a person is diagnosed with color blindness, he, alas, does not have the right to drive a vehicle.

The colors of the rainbow delight us aesthetically and serve as visual cues, but do we really need all that? This is worth thinking about.

When an architect plans the design of a building, he takes into account all the little details to ensure that the guests are happy, so that even people with physical disabilities feel comfortable in it. But does anyone take color vision disorder into account?

Probably, since such disorders are invisible to a person's appearance, many people do not even think about it or try to do anything about it. After all, how can you explain to a person what the color green looks like if he has never seen it?

Of course, you can try to describe this color, but still a colorblind person will not be able to imagine it the way ordinary people see it. Colorblind people often feel frustrated in everyday life.

They try to buy dull, solid-colored clothes so as not to accidentally come to a party in a multi-colored and mismatched outfit. Children feel awkward during an art lesson if the pencils or paints do not have index marks.

And the hardest thing is probably to listen when other people talk about beautiful, bright things, but you cannot see them. And although colorblind people cannot become pilots, electricians or makeup artists, there are a number of other professions in which they can express themselves. For example, graphic design.

Colorblindness and design

Don't jump to conclusions. This job may actually suit the colorblind. First, website designs don't always rely solely on different colors to highlight important information. Website designers also use other ways to attract attention, such as different fonts or contrast.

Secondly, all colors on the Internet are arranged in hexadecimal. Blue color, like all others, has its own code - #0000FF. Therefore, people who are color blind can remember the shade codes and easily color website pages.

Why do some people see colors and others cannot?

It is still not possible to answer this question completely. It is known that the cells located in the retina of the human eye, similar in shape to a chemical flask (they, by the way, are called cones), are divided into three types.

Each type of cell is excited by one of three colors: red, green or blue. True, they all react to other colors. The cells contain special colored substances - pigments that transmit light waves only of a certain length.

Excitation of one “type” of cells gives a feeling of the corresponding color, except for white, which is obtained when all cones are “turned on.” All other colors and shades are complex variations of intermediate states.

If one of the pigments is missing in the cones, then a person cannot see the corresponding color. In addition, due to this loss, the perception of some shades is also distorted. This theory, however, does not explain all congenital color perception disorders.

Therefore, scientists have recently suggested that colorblind people have a slightly different pigment that does not perform its duties well. The following situation is also possible: the pigments are normal, but they end up in “not their own” cells - for example, a “green” pigment ends up in “red” cones.

This confusion also makes it difficult to transmit other normal signals to the brain. But explaining does not mean curing. Unfortunately, there are no methods for treating congenital color blindness yet (although contact lenses have appeared in the West, with the help of which colorblind people can see the world in its pristine beauty).

And now about why such a scourge falls mainly on men. Genetics were able to answer this question. It turned out that the “responsibility” for the occurrence of color blindness in men lies with women.

They are the hidden carriers of a defective gene that causes color vision impairment. Why does this gene manifest itself in a male body, but not in a female body? The fact is that the pair of chromosomes responsible for a person’s gender exists in two versions.

In women its components are identical, but in men they are not. Female sex chromosomes are usually designated by the Latin letter “X”. Women have two X chromosomes (XX), and men, in addition to the X chromosome, also have a small chromosome, which is designated by the Latin letter “Y”.

That is, the “gentleman’s” set is XY. The gene for color blindness lies on the X chromosome, and its “strength” is low. If a person has a normal, unmodified gene, then it cannot express itself.

It is clear that in women with two X chromosomes, the appearance of congenital color blindness is possible only if there are defective genes on both chromosomes. This situation is extremely rare.

But there is no gene on the Y chromosome that can “silence” its unsuccessful partner, so the color blindness gene manifests itself quite often in men. Surprisingly, many people with impaired color perception learn about this feature of theirs by accident.

It turns out that they gradually “learn” to distinguish colors according to their degree of brightness, which partly compensates for their deficiency. Moreover, they do this so successfully that only a specialist can “expose” this roundabout way of perception.

Types of hereditary color blindness

There are 4 main types of color blindness:

Dichromasia . This pathology develops when any of the three types of cone cells are missing from the retina. With dichromasia, patients can detect differences between blue and yellow, but are unable to distinguish between green and red. The disease is not considered too severe, but still reduces a person’s quality of life.
Anomalous trichromasia . The most common color vision disorder. These patients have all three types of cone cells, but one of them has developed a deficiency of the pigments responsible for the perception of shades. The symptoms of abnormal trichromasia are as follows: patients see any color, but they perceive blue, green, and red somewhat differently than healthy people.
Blue cone monochromasia . In this case, people do not have two cone cells, which are responsible for the perception of green and red. This disease is exclusively a male “privilege”. People who have developed blue cone monochromasia can only visualize the blue color spectrum. Many of them have blurry vision into the distance. Young children often develop nystagmus - uncontrolled movements of the eyes.
Retinal rod monochromasia, or achromatopsia . The patient does not have any type of cone cells on the retina of the eye. When this type of disease appears, the patient can distinguish between gray, white, black, and does not see any of the colored shades. Most people with achromatopsia suffer from other eye diseases. As a rule, they are all nearsighted - they have difficulty distinguishing objects at a distance, even when reading they have odd vision, their eyes are very sensitive to light. This disease is the most severe, but is very rare.

Acquired color blindness

The causes of this type of color blindness are many different factors, disorders and diseases. One of the prerequisites for the development of color blindness may be age-related degenerative changes, as a result of which the lens loses its transparency. As a result of such processes, a person cannot see dark blue, dark green, dark gray shades.

In some cases, color perception is impaired due to the pathogenic effects of medications or after an overdose. The nature of such changes in vision is permanent or temporary.

In addition, color blindness can be caused by ophthalmological diseases - retinopathy of diabetics, lesions and degeneration of the macula, glaucoma and cataracts. It is possible to restore normal vision only with early consultation with a doctor and selection of the correct treatment and elimination of all factors leading to the appearance of color blindness.

Sometimes color blindness can occur after injuries or other damage to the organ of vision.

Ways of transmission of color blindness

Source: moeoko.ru
The transmission of color blindness depends on which parent has the defective gene and on the gender of the child who receives this gene. The disease occurs more often in men, although it is transmitted through the female line. The gene is found on the sex chromosomes and is recessive.

The mother may be a carrier of a recessive gene, but since she has two XX chromosomes, the second chromosome blocks the defective one and she will not get sick. But the father has XY chromosomes, and his disease is fully manifested.

X chromosomes are sex chromosomes that contain the color blindness gene. Inheritance of color blindness by sons occurs only from the mother. If both parents suffer from this disease, then the gene is passed on to the daughter. But this happens quite rarely.

In some cases, this type of disease is acquired. Color vision impairment occurs in people due to:

brain injuries or disorders of the central nervous system,
prolonged motion sickness in transport or on a ship,
constant work at the computer (temporary violation),
eye injuries that damage the optic nerve,
darkening of the lens or cataracts,
taking a number of medications without a doctor’s prescription.

The impairment may be temporary or permanent depending on the origin of the disease or its cause.

How is color blindness inherited?

Let's see how color blindness is inherited with different types of combinations of defective and healthy genes:

The woman is healthy (XX), and the man is color blind (X*Y). The daughters will get the recessive gene and they will become its carriers (X*X), but they will not get sick. The sons will grow up healthy, as they inherit only the Y chromosome from their father. The disease will not manifest itself in such a family.
The woman is a carrier of the diseased gene (X*X), the man is healthy. In 50% of cases, daughters will be carriers of this gene, but the disease will not manifest itself. Sons will be healthy in 50% of cases (XY) and sick in 50% of cases (X*Y). Inheritance occurs in 25% of cases and only in boys.
The woman is a carrier of the color blindness gene (X*X), the man is sick (X*Y). Half of the daughters will receive a defective chromosome, but will not get sick (X*X), the other half will be sick (X*X*). The disease will be transmitted to sons in the same proportions: 50% (XY) and 50% (X*Y). The disease will manifest itself in 50% of cases, i.e. Half of the children will get sick.
The woman is colorblind (X*X*), the man is healthy (XY). Girls in the family will be carriers of the diseased gene, since they will receive a second, healthy gene from their father, and the transmitted diseased gene will be in the sons. All boys in the family will be sick (X*Y).
If both parents are colorblind, then all children will be sick, since the colorblind gene will be passed on to daughters and sons. The disease is 100% inherited.

To identify the disease, polychromatic tables are used, on which figures or numbers are depicted using multi-colored dots. The patient will not see different colors; for him it will be a blurry, gray background. Inheritance affects both eyes.

The inheritance of color blindness is related to the sex of the child. The risk of getting this disease is much greater in boys, while girls for the most part do not get sick, but their genotype may contain a diseased gene. Color blindness is inherited from generation to generation, it can be traced through the family tree.

Symptoms

Color blindness, as a rule, has only one symptom - a violation of the correct perception of colors. The patient does not experience any unpleasant sensations, and visual acuity does not change. It is especially difficult to diagnose the disease in children, since they have an established idea of the a priori nature of the colors of the environment, imposed by adults (grass is green, the sky is blue, and so on).

Congenital color perception disorder

It has been established that, being quite rare diseases, hemophilia and color blindness are hereditary traits. Partial or complete color blindness can be congenital, inherited, or acquired. The latter is less common.

Hereditary color blindness is a recessive trait that is associated with pathology of the X chromosome. That is why the disease most often affects males, who inherit it from their mother. That is, as a hereditary trait, color blindness is linked to the X chromosome.

Hereditary color blindness cannot be cured, but it can be corrected with the help of special glasses. Although it is impossible to say with one hundred percent certainty that they will give the desired result.