How colorblind people see the world, the colors they cannot distinguish

https://twizz.ru/wp-content/uploads/2021/02/1614250877_8c7dd922ad47494fc02c388e12c00eac.jpg
If the science of style dictates its own rules to us when choosing a color palette in clothes, one can imagine how difficult this task becomes for people suffering from color blindness. In fact, it turns out that this problem is familiar to a much larger number of people than we used to think, because according to statistics, 1 in 200 women and 1 in 12 men around the world experience color blindness.

However, contrary to popular belief, colorblind people do not see the world only in black and white, and this is the topic of a fascinating issue of the Asian fashion blog YesStyle.

While people with full vision can see all the colors and shades in the pictures, people with color blindness will see a less bright and colorful picture. And you have the opportunity to see it with your own eyes!

Causes of color blindness

How colorblind people see is due to subtypes of the disease, each of which is caused by certain deviations. The most common cause is a malfunction in the development of one or more cone-shaped visual cells, which sense color and transmit information to the optic nerve. This type of colorblindness is usually dictated by gender. The genes that produce photochromic substances are contained on the X chromosome. If some of them are damaged or missing, men are more likely to develop the disease because they only have one of this type of cell. Women have two X chromosomes, so usually the missing substances can be replenished. Color blindness can also result from physical or chemical damage to the eye, optic nerve, or parts of the brain. For example, people with achromatopsia completely lack the ability to perceive colors, although the impairments are not of the same nature as in the first case.

Types of color blindness

It is very difficult to determine the factors for the development of color blindness, but in this case it is important to understand how the abnormal process . The problem in modifying the spectral sensitivity of the main pigments causes disturbances in reality, as well as in the perception of the picture. If there is no blue pigment on the retina of the eye, and this manifestation is caused by a hereditary factor, then successful treatment will be very difficult.

If the patient can distinguish between red and other shades, but confuses them, and such a pathology is acquired, then it can be eliminated by wearing special glasses. You can fight the inability to normally perceive the world around you; everything will directly depend on the type of eye pigmentation and the type of trichromasia.

1. Complete color blindness. This form of the disease affects both women and men. And the process of disruption is preceded by a whole group of factors. If people cannot perceive absolutely all shades, then we are talking about a full form of trichromasia. The disease is very rare, severely limits a person’s capabilities, for example, he definitely cannot become an artist and is prohibited from driving a personal car (serious problems arise with traffic lights). All three membranes and their improper formation are also involved in pathological processes.
2. Partial type. Such patients can perceive colors and some shades normally, but sometimes people still confuse some shades and see everything incorrectly.
3. Deuteranomaly. A sick person may have difficulty perceiving the color green and all other shades. Real photographs of how colorblind people perceive the world in this case can be viewed on special websites, as well as medical resources.
4. Protanomaly. Any person knows who is colorblind and what is his peculiarity, but only those patients who have a violation of the perception of red color and its main shades are faced with such a disease. They see everything around differently, but in more saturated colors.
5. Tritanomaly. A person does not see violet and blue colors; instead, objects in the mind of a colorblind person become red or green. This in no way prevents a person from continuing to live a full and rich life , but some difficulties are still present.

This is interesting

In 1798, the English chemist John Dalton published the first scientific work on this topic, thanks to which the general public became aware of how colorblind people see. His study, “Unusual Facts about the Perception of Colors,” was the result of realizing his own illness: the scientist, like some other members of his family, did not see shades from the red spectrum. Colorblindness is generally considered a mild disability, but in some cases it offers certain benefits. Thus, some researchers have concluded that those suffering from color blindness are better able to distinguish camouflage. Such discoveries may explain the evolutionary reason for the high prevalence of color blindness in the red and green spectrum. There is also research suggesting that people with some types of the disease are able to see colors that others cannot see.

Normal color vision

To understand how colorblind people see colors, it is necessary to consider the mechanism of perception in general. The normal retina of the human eye contains two types of light-sensitive receptors, the so-called rods and cones. The former are responsible for vision at dusk, while the latter are active in daylight. There are usually three types of cones, each containing a specific pigment. Their sensitivity is not the same: one type is excited by a short wavelength of light, the second by a medium wavelength, and the third by a long wavelength, with peaks in the blue, green and yellow regions of the spectrum, respectively. Together they are supposed to cover all visible colors. These receptors are often called blue, green and red cones, although this definition is not precise: each type is responsible for the perception of a fairly wide range of colors.

For what reasons is color perception distorted?

In colorblind people, the cones on the retina do not perform their function properly.
A person is capable of 5 senses, one of them is to see the world with the help of the eyes. Suddenly it turned out that people react differently to colors in the same pictures. In every deviation from the norm, not like everyone else, there must be a reason for such a departure from the general characteristic.

Doctors considered this manifestation to be impaired color perception, although there is debate about color blindness. They do not consider some forms to be a disease, but a feature of the visual sensation of color. Since people of this category are endowed with the ability to distinguish shades inaccessible to other ordinary individuals.

The manifestation of unusual vision was not considered dangerous for a long time; they did not even know about the existence of such manifestations in human eyes, until a learned Englishman noticed a feeling in himself that was distinctive from the rest of society. But with the development of science and technology, emergency situations were created due to visual impairments. One of the first to commit a disaster that claimed many lives on the railway was a color-blind driver who could not distinguish between red and green.

Since then, they began to set restrictions on professions whose activities depend on the specialist’s ability to perceive color.

The reason for the unusual perception of the color palette lies in the color-sensitive receptors located in the retina. Nerve cells are called cones.

There are three types of them, of protein origin, each responsible for its own pigmentation:

• red;
• blue;
• green.

Trichromats or pigments in humans without disturbances filled the cones with all three shades in the required quantities. When some pigment is missing, vision problems begin, manifested as color blindness.

It can be congenital and acquired. Pathology is inherited from the mother using the “X” chromosome. Women's genetics are able to compensate for a damaged particle as a whole; the male body is not endowed with such functions, so they are more often susceptible to color blindness. The nature of the acquired anomaly is presented more simply.

The reasons are as follows:

1. the impact of medications used;
2. the retina is injured by physical penetration of a foreign body;
3. the optic nerve is damaged;
4. There was a sunburn of the eyeball.

The acquired disease is not limited by gender, and people have difficulty distinguishing between yellow and blue shades in the general variety of colors.

How do colorblind people see the world? Classification

In the clinical picture, a distinction is made between complete and partial color blindness. Monochromasia, complete color blindness, is much less common than the inability to perceive individual shades. The world through the eyes of a colorblind person with this disease looks like a black and white movie. The disorder is caused by a defect or absence of cones (two or all three), and color perception occurs in one plane. As for partial color blindness, from the point of view of clinical manifestations, there are two main types of it, associated with the difficulty of distinguishing between red-green and blue-yellow.

• Complete color blindness.
• Partial color blindness.
• *Red Green.
• **Dichromasia (protanopia and deuteranopia).
• **Anomalous trichromasia (protanomaly and deuteranomaly).
• *Blue yellow.
• **Dichromasia (tritanopia).
• **Anomalous trichromasia (tritanomaly).

Classification of color blindness

There are two types of color blindness: complete and partial.

Complete (monochromasia, achromatopsia)

Caused by the absence or abnormal development of all three types of cones. At the same time, a person sees everything in black and white. As already mentioned, such an anomaly is extremely rare;

Partial

Partial is divided into the following types:

1. Dichromasia (dyschromatopsia) , in which one type of cone is not involved in color perception. People suffering from dichromasia are called dichromats. Depending on what type of receptors is damaged, dichromasia is divided into:

• Protanopia, in which there is no perception of the red spectrum;
• Deuteranopia, in which the perception of the green spectrum is impaired;
• Tritanopia, in which the blue part of the spectrum is not perceived.

2. Abnormal trichromasia . This is a condition in which a person's ability to perceive one primary color is reduced (but not completely lost). Similar to dichromasia, there are three types of disorders: protanomaly, deuteranomaly and tritanomaly.

The frequency of occurrence of each anomaly is presented in the diagram:

Depending on the cause of its occurrence, color blindness occurs:

• Congenital or hereditary . It passes from mothers to sons. The fact is that the gene leading to color blindness is localized on the X chromosome and is dominant. As you know, the genotype of a man is represented by the XY set, and that of a woman by the XX set. Thus, if a mother is a carrier of an abnormal gene, she will pass it on to her son in 100% of cases. A woman can only get sick if both her parents suffer from color blindness. This happens extremely rarely (you can read more here);
• Purchased . Develops as a result of diseases of the optic nerve and retina (cataracts, macular degeneration, glaucoma, diabetic retinopathy). More often it is unilateral (that is, one eye does not distinguish colors). Acquired color blindness can be reversible (if the underlying disease is successfully treated).

Now let's look at how colorblind people see colors, depending on the type of colorblindness.

Dichromasia

Dichromasia is a disorder of moderate severity and consists of improper functioning of one of three types of receptors. The disease occurs when a certain pigment is missing, and color perception occurs in two planes. There are three types of dichromasia based on which type of cone cell is not working properly:

• first: Greek “prot-” - red;
• second: “deitra-” - green;
• third: “trit-” - blue.

Want to know how colorblind people see? A photo can give a clear idea of ​​the features of their picture of the world.

Color blindness in children

The disease goes unnoticed for a long time, since color-blind children perceive some tones and shades by ear, the method of associations works. They distinguish the colors of the surrounding world in their own way and do not realize that this is wrong. Falling out of the color spectrum is determined later, when the child begins to think clearly and analyze what is happening. The problem is not global, but it significantly disrupts the usual rhythm of life and deprives one of prospects. Doctors do not exclude the presence of other unpleasant symptoms:

• weakened visual acuity;
• progressive nystagmus;
• twilight vision impairment.

Forms of dichromasy

• Protanopia is a disorder in which an individual can perceive light with a wavelength of 400 to 650 nm instead of the usual 700 nm. It is caused by complete dysfunction of red photoreceptors. The patient does not see pure scarlet flowers, which appear black to him. Purple is no different from blue to an individual, but orange appears dark yellow. All shades of orange, yellow and green, whose wavelengths are too long to stimulate blue receptors, appear as a similar yellow tone. Protanopia is a congenital, gender-related disorder that occurs in approximately 1% of men.
• Deuteranopia involves the absence of type 2 photoreceptors, which causes difficulty in distinguishing between red and green.
• Tritanopia is a very rare disorder characterized by a complete absence of blue pigment. This color appears greenish, yellow and orange appear pinkish, and purple appears dark red. The disease is associated with the 7th chromosome.

What colors are most often confused?

Difficulties with color perception arise in a person when he lacks one or more pigments (cones) in the retina of the eye, which are responsible for sensitivity to a certain color.

For example, in the case of protanopia, instead of a red hue, a person perceives brown, violet is replaced by blue, orange is seen as dark yellow. Pure scarlet tones appear black or gray. Yellow stays yellow.

Protanope is able to confuse all shades of green and orange colors: they seem yellow to him.

With deuteranomaly, instead of green, a colorblind person perceives light orange. In this case, green objects may appear red, orange, or brown. Objects of red color acquire a greenish tint and are perceived by humans as blue-green.

Deuteranope can see leaves on trees as blue or dark brown.

With difficulty recognizing blue and violet (tritanopia), the world appears to a colorblind person in muted brown shades. Blue and yellow tones look the same, lilac objects are perceived as red.

This form of color blindness is often combined with weakened twilight vision - a deterioration in visual abilities in the dark.

What colorblind people see: anomalous trichromasia

This is a common type of congenital color vision disorder. Anomalous trichromasia occurs when the spectral sensitivity of one of the pigments is modified. The result is a distortion of normal color perception.

• Protanomaly is a minor defect in which the spectral sensitivity of red receptors changes. There is some difficulty in distinguishing between scarlet and green colors. The congenital disease, determined by gender, occurs in 1% of men.
• Deutranomaly is caused by a similar shift, but in the green spectrum. This is the most common type, influencing to some extent the color discrimination from the previous case. The disorder is hereditary and gender-related and occurs in 5% of European men.
• Tritanomaly is a rare disorder that affects blue-green and yellow-red discrimination. Unlike other forms, it is not determined by gender and is associated with the 7th chromosome.

Description of forms of color blindness

Scientists have developed a special classification that distinguishes forms of color blindness by colors that a person cannot distinguish.

Achromasia is commonly called the absence of color pigments in all cones of the retina, which leads to a complete inability to see any shades other than gray. Fortunately, this type of color blindness is diagnosed in very rare cases.

With monochromasia, the patient can see only one color. In addition to impaired color perception, nystagmus and photophobia are often encountered in this case.

People suffering from dichromasia distinguish between 2 colors. Dychromasia is divided into:

• protanopia (a person does not see the color red);
• deuteranopia (a person cannot see the color green);
• tritanopia (a person cannot see the color blue and suffers from “night blindness”).

Diagnosis and treatment

The Ishihara test contains a series of images consisting of colored spots. The figure (usually Arabic numerals) is embedded in the design as dots of a slightly different shade, which can be distinguished by people with normal vision, but not with a certain type of disorder. The full test involves a series of images with different combinations to reveal whether the disorder is present and specifically what colors colorblind people cannot see. For children who do not yet know numbers, drawings with geometric shapes (circle, square, etc.) were developed. Diagnosis of anomalous trichromasia can also be made using an anomaloscope. Currently, there is no effective treatment for color blindness in humans. Colored lenses may be used to improve the ability to see some colors but make it more difficult to see others correctly. Scientists are conducting trials to treat color blindness using genetic engineering methods, which have already yielded positive results in a group of monkeys.

How is color blindness inherited?

It is important to clearly understand that this disease develops with different types of combinations of defective and healthy genes. Possible genetic combinations are presented below, which help determine the disease even when a woman is planning a pregnancy:

1. The mother is healthy, the father is colorblind. Born daughters inherit the recessive gene, become its lifelong carriers, but do not get sick themselves. Sons are also born completely healthy, since they receive only the Y chromosome from a sick father. With this combination, the diagnosis is not dangerous.
2. The mother is a carrier of the defective gene, the father is completely healthy. Daughters become 50% carriers of an incurable disease, but they themselves do not get sick. Color blindness in born boys is detected 50% to 50%, so in this case it is very problematic to predict the clinical outcome.
3. The mother is a carrier of a defective gene, the father is sick and is congenital color blind. The probability of manifestation of a characteristic disease in born sons and daughters is 50% to 50%; it is difficult for doctors to predict the clinical outcome. After birth, the child is observed by an ophthalmologist for timely detection of the first symptoms of the disease.
4. The mother is sick, the father is healthy. Girls become passive carriers of the gene and do not get sick themselves, while boys born into such a family definitely face congenital color blindness. The diagnosis is incurable, representatives of the stronger sex grow up colorblind.
5. Mother is colorblind, father is colorblind. A child, regardless of gender, also has this disease, which is congenital and cannot be successfully treated conservatively or surgically. Biological parents need to know about this when planning a pregnancy.

Article on the topic: Heboid syndrome - an explosive mixture of schizophrenia, psychopathy and antimorality