Color blind people are people who cannot distinguish certain colors. Sometimes it can be one color, for example: red, green or purple. And sometimes (very rarely) some or all - the world looks black and white. Moreover, this is not considered a disease, but a feature of perception.

A person may not even suspect that he sees colors differently from others. This can be revealed by chance or with the help of a special picture, which for color blind people does not look the same as for a person with ordinary color perception.

How to identify - is there a violation of color discrimination?

There are a lot of tests that help determine color blindness, but most of them only detect the difference between green and red colors. Among them, Rabkin's polychromatic tables were recognized as the most perfect. With their help, you can determine both the type of color blindness and the state of color perception of a person.

Tests from the Rabkin table are pictures with circles of a certain color range and numbers or figures hidden among them. A person with a normal color perception sees the "filling" immediately, but color blind people need to try to see it. In some cases, attempts may not be successful.

Below is a table showing pictures for verification. To pass the test, you need to look at them all and see what is depicted on them. The tests are carried out in normal daylight at a distance of 1 m from the table. In this case, the pictures cannot be turned over, they must be vertically, i.e. they cannot be viewed, even if they are on a table or in an inclined state. This can affect the correctness of the result. After the table, the correct answers will be presented (they are located in accordance with the arrangement of the pictures) for comparison with your own.

You need to look at each test (picture) no longer than 5 seconds (click on the picture to enlarge it):

Now let's compare the results with the correct answers:

If there are too many wrong answers, then this may indicate a pronounced color blindness.

Korean designers have proposed improving the traffic light to allow color blind people to drive. They propose to change its shape. Namely: red is a triangle, green is a square, yellow is a circle.

Interpretation of test results

To understand what kind of color blindness you can rank yourself with, consider briefly the types of color blindness. If we talk about a minor violation of color perception - trichromasia, then it can be divided into the following types:

1. Deuteranomaly is a violation of the perception of green color (it is mixed with a light pink or light orange tint).
2. Protanomaly - incorrect perception of red (it mixes with a light brown or light green tint).
3. Tritanomaly is not a distinction between blue-violet colors (they are seen as red or green; rare).

If we talk about more serious violations (distinguishing only two colors), then these are:

1. Deuteranopia - everything looks green.
2. Protanopia - everything appears red.
3. Tritanopia - the world seen in shades of blue.

Another type of violation of color perception is monochromaticity. This is when everything is seen in black and white. But such a phenomenon, like tritanopia, is very rare (1 in 300 cases of color blindness).

Well, now you can start interpreting the results. Let's look at the example of several pictures, what can mean seeing / not seeing what is drawn there.

See the number 96 in this picture? Not? Do not try to deceive anyone, this is a control test used to identify simulators. They are visible to absolutely all people:

And what can be seen here? The correct answer to the test is 13. If the number 6 is seen, then this may indicate protanopia or deuteranopia.

Normally, here you need to see the number 96. With color blindness, only the number 6 is visible.

This test is with the number 136. Numbers 68, 69 or 66 may indicate color blindness.

The norm is a circle and a triangle. Protanopes here will see only the second figure, deuteranopes - a circle (but they can also see both figures).

A person with normal color discrimination at the top of the table will see two numbers - 3 and 0. With protanopia - 1 and 0 at the top, 1 at the bottom (normally not visible), with deuteranopia - at the top 1, below 6.

If the result is not happy, then don't panic. Since the correctness of the answers may depend on lighting, monitor resolution, viewing distance, etc.

Video test for color blindness "Check yourself!":

The tests presented are approximate and cannot form the basis for an independent diagnosis. Only an ophthalmologist can accurately determine the type and state of color blindness by testing according to all the rules, or after checking on an anomaloscope.

Have you compared your answers with the correct ones? What did you do! Write about it in the comments!

To identify color blindness (color blindness) and its manifestations in modern ophthalmology, Rabkin's polychromatic tables are used. According to the degree of color perception, ophthalmologists distinguish: trichromants (the norm), protoanopes (people with impaired color perception in the red spectrum) and deuteranopes (people with impaired green color perception).

To pass the color blindness test, you should adhere to certain recommendations:
- the test is carried out with normal health
- first you need to relax
- try to keep the picture and eyes on the same level during the test
- up to 10 seconds are given to view the picture

Picture 1

The picture shows the numbers “9” and “6”, which are visible to both people with normal vision and people with color blindness. The picture is intended to explain and show people what exactly is required to do when passing the test.

Picture 2

This picture shows a square and a triangle, which are visible, as in the previous version, to people with normal vision and people with color blindness. The picture is used to demonstrate the test and to identify the simulation.

Figure 3

The picture shows the number “9”. People with normal vision see correctly, while people with red or green blindness (deuteranopia and protanopia) see the number “5”.

Figure 4

The picture shows a triangle. People with normal vision see the triangle depicted, while people with blindness in the red or green part of the spectrum see a circle.

Figure 5

The picture shows the numbers “1” and “3” (answer “13”). People with blindness in the red or green part of the spectrum see the number “6”.

Figure 6

People with normal color perception distinguish two geometric shapes in the picture - a triangle and a circle, while people with blindness in the red or green part of the spectrum are not able to distinguish the figures shown in the picture.

Figure 7

The picture shows the number “9”, which can be distinguished by both people with normal color perception and people with color blindness.

Figure 8

The picture shows the number “5”, which is able to distinguish between people with normal vision and people with blindness in the red or green part of the spectrum. However, for the latter, this is difficult or even impossible.

Figure 9

People with normal color vision and people with blindness in the green part of the spectrum can see the number "9" in the picture, while people with blindness in the red part of the spectrum can see both the number "9" and "8" or "6".

Figure 10

People with normal vision distinguish the numbers “1”, “3” and “6” in the picture (answer “136”), while people with blindness in the red or green part of the spectrum see “69”, “68” or “66”.

Figure 11

The picture shows the numbers “1” and “4”, which can be seen by both people with normal color perception and people with color blindness.

Figure 12

The picture shows the numbers “1” and “2”, which are able to distinguish both people with normal vision and people with blindness in the green part of the spectrum, while people with blindness in the red part of the spectrum do not see numbers at all.

Figure 13

The picture shows a circle and a triangle that people with normal color perception are able to distinguish. At the same time, people with blindness in the red part of the spectrum in the picture see only a circle, while people with blindness in the green part of the spectrum only see a triangle.

Figure 14

People with ordinary color perception in the picture will distinguish between the numbers “3” and “0” in the upper part, while they will not see anything in the lower part. Whereas people with blindness in the red part of the spectrum will distinguish between the numbers “1” and “0” in the upper part, and the hidden number “6” in the lower part. And people with blindness in the green part of the spectrum will see “1” above, and “6” at the bottom of the picture.

Figure 15

People with normal color perception in the picture will distinguish a circle and a triangle (in the upper part), but they will not see anything in the lower part. People with blindness in the red part of the spectrum will see 2 triangles (top) and a square (bottom). People with blindness in the green end of the spectrum will distinguish between a triangle (top) and a square (bottom).

Figure 16

People with ordinary color perception in the picture will distinguish the numbers “9” and “6”, while people with blindness in the red part of the spectrum only “9”, and with blindness in the green part of the spectrum - only “6”.

Figure 17

People with normal color perception see a circle and a triangle in the picture, while people with blindness in the red part of the spectrum only a triangle, while people with blindness in the green part of the spectrum only a circle.

Figure 18

People with ordinary color perception in the picture will see multi-colored vertical and monochrome horizontal rows. At the same time, people with blindness in the red part of the spectrum will see horizontal rows as one-color, and vertical rows 3, 5 and 7 as one-color. People with blindness in the green end of the spectrum will see horizontal rows as multi-colored, and vertical rows 1, 2, 4, 6, and 8 as monochrome.

Figure 19

People with normal vision are able to distinguish the numbers “2” and “5” in the picture, while people with blindness in the red or green part of the spectrum will see only the number “5”.

Figure 20

People with ordinary color perception are able to distinguish two geometric shapes in the picture - a triangle and a circle, while people with blindness in the red or green part of the spectrum will not be able to distinguish the depicted figures.

Figure 21

In the picture, people with normal color perception and people with blindness in the red part of the spectrum will distinguish the numbers "9" and "6", while people with blindness in the green part of the spectrum will see only the number "6".

Figure 22

The picture shows the number "5", which can be distinguished by both people with normal color perception and people with manifestations of color blindness. However, for the latter it will be difficult or even impossible to do this.

Figure 23

In the picture, people with normal vision will see multi-colored horizontal and monochrome vertical rows. At the same time, people with blindness in the red or green part of the spectrum see monochrome horizontal and multi-colored vertical rows.

Figure 24

In the picture, the number "2" is seen by people with normal vision, protanopes and deuteranopes do not distinguish this figure.

Figure 25

Trichomats (people with normal vision) see the number "2" in the picture, people with blindness in the green and red parts of the spectrum, the number "2" cannot be distinguished.

Figure 26

People with normal color perception distinguish two shapes in the picture: a triangle and a square. People with blindness in the green and red spectrum, these figures do not distinguish.

Figure 27

Normal trichomes see a triangle in the picture, people with color vision disorders distinguish a "circle" shape

Outcome:

It should be noted that if you answer the wrong answer, you do not need to start to panic, since perception can depend on a number of factors: the illumination of the office, excitement, the matrix of the monitor and its color (when passing the test online), etc.
If abnormalities are detected with a free online eye exam, it is recommended to see a specialist for a more thorough diagnosis.

Color blindness, or in another way - color blindness, as a rule, is a hereditary or much less often acquired disease of the organ of vision, which is expressed in a violation of the normal perception of color.

According to statistics, men are most often affected by this disease. To find out if you have this anomaly, you need to do special testing. It has great importance if you have plans to purchase and drive a car.

Classification of color blindness

The disease can occur in both partial and complete forms:

• the most common case is redness or protanopia;
• immunity of blue-violet color - dichromia-tritanopia;
• immunity of green color - deutranopia;

In modern ophthalmology, color blindness (color blindness) and its manifestations are detected using a test with Rabkin's polychromatic tables. Tables are a kind of drawings, where points and circles of different colors and diameters are depicted. In the presence of color blindness, a person can easily distinguish the brightness of a color, but the color itself is difficult for him to characterize. Rabkin's scheme takes these features into account - the brightness of the icons is the same, but the color is different. A person with a deviation in color perception will not see an image hidden in a different color in the scheme.

The set of tables consists of two groups:

1. The main group - tables 1 to 27, are intended for differential diagnosis of the forms and degrees of color vision disorders.
2. Control group - tables 28 to 48 are intended to clarify the diagnosis.

Test conditions for color perception

• The study must be carried out under natural light and the subject's normal state of health.
• The patient should sit with his back to the window, and the test taker opposite.
• Polychromatic tables must be presented vertically, at the same level with the eyes, with a distance of 1 meter.
• It takes about 5 - 7 seconds to view the picture and answer.
• You do not have to read the result before viewing the card, first we look at the picture for 5-7 seconds and then we read the result, because it is easier for the brain to find what it knows.

Color blindness test according to Rabkin tables

Table 1

The table shows the number "96", which is well recognized by both people with color blindness and people with normal vision. The goal is to visually show the examinee what exactly needs to be done during the test.

table 2

The table shows figures - a triangle and a square. They are perfectly seen by healthy people who are good at recognizing the colors of the spectrum, and people with color blindness. The goal is to demonstrate the test and identify the simulation.

Table 3

The table shows the number "9". If an anomaly is present, the person will distinguish the number "5".

Table 4

With normal color perception, a triangle and, less often, a circle are visible in the table. If an anomaly is present, then the person will see a circle.

Table 5

With normal color perception, the figure "13" is visible in the table. If an anomaly is present, then the person will see the number "6".

Table 6

Under normal color perception, two shapes are visible in the table: a triangle and a circle. If there is an anomaly, then the person will not distinguish the figures at all.

Table 7

The table shows the number "9". It is perfectly seen by healthy people who are good at recognizing the colors of the spectrum, and people with color blindness.

Table 8

The table shows the number "5". It is perfectly seen by healthy people who are good at recognizing the colors of the spectrum, and people with color blindness. However, color blind people can hardly distinguish this figure.

Table 9

The table shows the number "9", which can be seen perfectly by both people who distinguish the color spectrum well, and people who are poorly oriented in the green part of the spectrum. If there is an anomaly in the perception of the red spectral part, the person will see the number "8" or "6".

Table 10

With normal color perception, the figure "136" is visible in the table. If there is an anomaly, then the person will see the numbers "66", "68", "69".

Table 11

The table shows the number "14", which is perfectly visible to healthy people who are good at recognizing the colors of the spectrum, and people with the disease color blindness.

Table 12

The table shows the number "12", which can be clearly seen by people who distinguish the color spectrum well, and people who are poorly oriented in the green part of the spectrum. People who cannot distinguish the red spectrum cannot distinguish these numbers at all.

Table 13

The table shows a triangle and a circle that people with normal color perception can see perfectly. People who are poorly oriented in the green part of the spectrum see only a triangle. If there is blindness in the red spectrum, the person sees only a circle.

Table 14

The table shows the numbers "3", "0", "6" which are perfectly distinguished by people with normal color perception. People who are poorly oriented in the green part of the spectrum will see the numbers "1" and "6". If there is blindness in the red spectrum, the person will see the numbers "6", "1" and "0".

Table 15

A healthy person will distinguish the following figures at the top of the table: on the left - a circle and on the right - a triangle, in some cases - a square at the bottom of the table. If there is blindness in the red spectrum, the person sees in the lower part - a square, in the upper part - 2 triangles. People with blindness in the green spectrum see a triangle at the top left and a square at the bottom.

Table 16

A healthy person will distinguish the number "96" in the table. If there is blindness in the red spectrum, the person sees only "9". A person who is poorly oriented in the green part of the spectrum will see only "6".

Table 17

A healthy person will distinguish the following figures in the table: a triangle and a circle. If there is blindness in the red spectrum, the person will distinguish only a triangle in the table. They see only a circle - people who are poorly oriented in the green part of the spectrum.

Table 18

People with a normal perception of color in the table will see monochrome horizontal and multi-colored vertical rows of squares. A person with red spectrum blindness will see horizontal rows as monochrome and vertically arranged - 3, 5 and 7 also in the same color. A person with blindness in the green spectrum will see horizontally arranged rows in different colors, and vertical rows 1, 2, 4, 6 and 8 in the same color.

Table 19

The table shows the numbers "2" and "5", which are excellent for people with healthy eyesight. People with a red or green spectrum perception abnormality will see only "5".

Table 20

People with healthy eyesight will distinguish the following shapes in the table: a triangle and a circle. If a person has blindness in the red or green spectrum, he will not distinguish the figures at all.

Table 21

The table shows the number "96", which is perfectly distinguished by both a healthy person and a person with an anomaly in the perception of the red spectrum. If the perception of green is distorted, a person sees only the number "6".

Table 22

The table shows the number "5", which will be seen by both a person with healthy vision and a person with color blindness. However, a color blind person will hardly distinguish this figure.

Table 23

In this table, people with healthy eyesight will see multi-colored horizontally arranged rows and single-colored vertically arranged rows. People with color blindness will see horizontal rows in one color and vertical rows in different colors.

Table 24

Table 25

With normal color perception, the figure "2" is visible in the table. If there is an anomaly in the perception of color, then the person will not see the number.

Table 26

Under normal color perception, two shapes are visible in the table: a square and a triangle. If there is an anomaly in color perception, then the person will not distinguish the figures.

Table 27

With normal color perception, a triangle is visible in the table. If there is an anomaly in the perception of color, then the person sees a circle.

Assessment of the test result:

• With any number of incorrectly recognized tables, a color vision anomaly can be assumed.
• Please be aware that the color calibration of your computer monitor may distort actual colors. A reliable result and, of course, the diagnosis can only be made by an ophthalmologist.

However, it should be noted that Rabkin's tables are recognized all over the world and are the most perfect of all existing tests that determine color blindness. They reliably establish the type and degree of change in color perception.

Nevertheless, if you have identified visual abnormalities online, we recommend making an appointment with a specialist for the final diagnosis. Be healthy!

Color perception test

Our ability to distinguish colors is determined by the presence of three types of light-sensitive elements (cones) in the retina. Each type of cone is sensitive to a specific region of the spectrum - red, green, and blue.

Some scientists believe that our animal ancestors had four-color vision, the fourth type of light receptors distinguished colors in the near ultraviolet part of the spectrum. And now some species of insects, birds and fish have similar vision. The mammals' predecessors lost their ability for four-color vision during the time of the dinosaurs, as they switched to a nocturnal lifestyle (there is no ultraviolet radiation at night).

Part modern people possesses four-color vision, their rods (a type of light receptor other than cones) provide a small area of ​​tetrachromacy (four-color) in the color space.

We invite you to test your color vision using a test developed by neuromarketing specialist Diana Derval. So, before you is a color picture in the shape of a rectangle, divided into vertical stripes of different colors. Count, starting from the left and moving to the right, how many colors you see.

Attention! Single-color zones (stripes) are not necessarily the same width! Having fixed in memory the number of distinguishable colors, proceed to assess your color perception.

Test results

Less than 20 colors. You have two types of light-sensitive cones in your eye; there are no cones that are sensitive to either red or green. There are also a quarter of people with color perception of this type (dichromats) on earth.

22 to 32 colors. You belong to that half of humanity whose eyes distinguish three colors. You are a trichromat, and you can distinguish many shades in all areas of the spectrum, from violet to red.

From 32 to 39 colors. You are from that quarter of people who belong to tetrachromats, you have the richest color perception, similar to that of a bumblebee. By the way, tetrachromats usually dislike yellow, it annoys them.

More than 39 colors. You fooled yourself - there are only 39 colors on the test. Full objectivity can only be obtained from a paper version of the high-quality print test.

The pathology of perception of different colors is not considered a common occurrence. Color blindness is more common among the male population, but cases of the disease are also found in the fairer sex.

Outwardly, a person can look absolutely healthy, and often he does not notice that he has vision problems.

Rabkin's technique involves conducting tests to establish a person's color perception. This is very important when choosing a profession.

Initially, passing the test can be encountered when it is necessary to obtain a driver's license; young people must pass this test during a medical examination before being drafted into the army.

The choice sometimes depends on the results of this test. professional activity, since people with such a pathology cannot engage in medicine, military affairs, or drive vehicles.

What is color blindness and its forms?

The inability to distinguish between the color palette of paints and shades is commonly called color blind.

The etiology of this pathological process is the change in the X chromosome. As a result, the patient has one or more color spectra of visual perception.

Normal color perception is based on three pigments:

• green,
• Red,
• blue.

Depending on the violation of pigment production, the following types of disease can develop:

• Deuteranopia. Sensitivity to color causes changes in the perception of green.
• Tritanopia. Color blindness extends to blue and its shades.
• Protanopia. The patient does not recognize red colors, perceiving them as dark brown or dark green.

To establish a diagnosis, they resort to using a color perception test according to the Rabkin method.

Test conditions for color perception

In order for the test results to be objective and reliable, certain conditions must be met:

Color perception test with Rabkin table

For the test for color perception, the Rabkin table is used.

It can be roughly divided into 2 parts:

1. In the main part of the test, there is a group of 27 images, which make it possible to establish the presence and degree of pathology of color perception.
2. The second part of the test has 21 pictures that provide confirmation and clarification of the diagnosis.

The test is based on the use of a combination of color palette, which allows you to identify pathological deviations in the perception of the color spectrum:

• When examining the first picture, color-blind patients and healthy people distinguish two numbers 9 and 6. It can be considered introductory, since it allows the subjects to adapt to the conditions of the test.

• The second image of the test is also indicative, but in addition, it allows you to identify cases of simulation. Patients with color blindness and people with normal color perception in this image see a square and a circle.

• Pathological color perception, the inability to distinguish between the red and green spectrum of the color palette makes it possible to recognize the number 5 in this image. A healthy person sees the number 9.

• A patient who has a pathology of color perception immediately notes that he clearly sees a circle in the picture, this is due to the fact that he cannot distinguish between red and green shades. Healthy vision allows you to see the triangle.

• The number 13 is on the test chart, color blindness does not make it possible to see it, and the subject sees the number 6.

• The triangle and the circle are seen only by a person who normally recognizes the color scale. Abnormal vision makes it impossible to distinguish any figures.

• The number 9, sometimes not without difficulty, is recognized by both sick and healthy people.

• When there are no abnormalities of visual perception, it is not difficult to see the number 5 in the picture. Deuteranomaly makes it difficult to recognize this number. The patient has to stare at the picture for a long time.

• The number 6 or 8 can be seen by people with abnormal red hue recognition. Abnormal perception of green and people without deviation of color perception in the image see the number 9.

• In case of pathology of color perception, the subjects claim that in the test picture the first symbol, the number 6, behind it they can distinguish, 6, 8 or 9. Normal vision allows you to see 1, 3, 6.

• With the same speed of reaction, both sick and healthy subjects note that the image of the number 14 is clear.

• 1 and 2 will not be seen only by those people who have a problem with recognizing the red tint. For other categories of persons, this part of the test will not cause difficulties.

• When recognizing a triangle at the bottom of the picture, and a circle at the top, it indicates that a person has a normal color perception. Patients with difficulty perceiving the green spectrum only notice the triangle. The visual deficit of the red spectrum recognizes only a circle. Both in the first and in the second case, the second figure remains unnoticed.

• When looking at the test chart, 3 numerical values ​​are distinguished. The number 3 is in the upper left corner, 0 is on the right, and the number 6 is in the middle and is slightly shifted downward. Such an arrangement is seen by a person without pathologies of color perception. Deuteranomaly allows you to see a 1 in the left corner of the figure, and in the center the number 6. Protanomaly suggests that the patient will see a 1 on the left, a zero on the right, and a 6 in the middle.

• This part of the test is more difficult, but normal color perception allows you to see a square in the central part, a circle on the left, and a triangle on the right. At that time, if a person has blindness in the perception of red, he sees two triangles on the sides, and in the central part of the image he speaks of the presence of a square. The inability to recognize the green color makes it possible for the subject in the upper part to see only the outline of the triangle, and below he notices the location of the square. The right side of the picture remains unrecognized.

• The combination of numbers 9 and 6 is an indicator of healthy color perception. A category of faces that recognizes only the 9 mark will indicate the impossibility of distinguishing red tones. The ability to see only the number 6 indicates the presence of a problem with the perception of green tones.

• The geometric shape of the triangle in the left corner, and the circle on the right can only be seen by people without visual pathology. The lack of the ability to distinguish between red shades allows you to see only the outline of the triangle. The limited green range of color perception allows the patient to see only the circle.

• This part of the test involves a visual examination of horizontally arranged geometric shapes in the form of small squares. The perception of a healthy person will allow us to note that the horizontal figures have the same shades, and the vertical squares have multi-colored colors. The deficit of the red spectrum will make it possible to see that the vertical rows numbered 3, 5 and 7 are monochrome, the limited perception of green tones will indicate that the horizontal squares are multi-colored. Vertical rows numbered 1, 2, 4, 6, 8, such patients will be perceived in the same color scheme.

• Color blindness of any form allows you to see only the number 5, although the table image has the number 25.

• Color blindness makes it impossible to see any geometric shapes or numbers in this image. Normal vision provides the ability to see the triangle and circle.

• 9 and 6 visually distinguish not only a healthy individual, but also a patient with abnormal recognition of the red tone. Only the number 6 is seen by patients who find it difficult to perceive green shades.

• If any color spectrum recognition anomaly is present, then at this stage of the test the subject will not see the image in the picture. Persons who do not have eye pathologies of color perception will indicate the presence of the number 2.

Evaluation of the results when passing the test for color perception

The presence of errors in the recognition of objects and numbers located on the tabular pictures of the test makes it possible to assume that a person has a disorder of light perception.

If the test was carried out behind a computer monitor, it is necessary to make a correction that there are cases when color calibration distorts the visible tabular image. Therefore, in such cases, it is better to have an examination by an ophthalmologist.

The method for assessing color perception using the Rabkin test is recognized as the most accurate in all countries of the world. In addition to the fact that the patient has color blindness, this technique allows you to determine which spectrum is not recognized by the visual organs.

The color blindness test is carried out when checking drivers, you can get checked by an ophthalmologist or online on a computer.

Conclusion

Color blindness is a serious pathology that is transmitted at the genetic level.

The male part of the population suffers from it more often (7%), women are less likely to get sick (1%), since they have a double pair of X chromosomes (it is when it is damaged that this pathology develops), which makes it possible to compensate for its shortage.

Until now, it was believed that this disease is not amenable to therapy, but American scientists have made a breakthrough in this direction.

Their new development - glasses for color blindness... And now people who have a color vision disorder can enjoy the color palette of the world around them.

They call the reduced ability or absolute inability of people to distinguish the colors of the spectrum, available for the perception of a person who does not have vision problems.

Cause

In the center of the retina there are receptors that are sensitive to different colors - a variety nerve cells, behind the shape called cones. There are three types of them, each with its own type of pigment:

• one gives susceptibility to red variants;
• the other is the ability to distinguish shades of green;
• the third one helps to see blue colors.

People who normally perceive the full spectrum are called trichromats. They have a standard set of pigments that are present in optimal quantities.

Origin

Color blindness is of the following types.

1. Congenital, that is, inherited.
2. Acquired, which can develop due to:

• damage to the retina or optic nerve;
• aging of the body, provoking development, contributing to a decrease in visual acuity and impairing color perception;

• taking a number of medications.

These color vision problems are classified. Dichromacy, in which a person distinguishes between two of the three primary colors. It happens:

• protanopic, which means the inability to see shades of red;
• deuteranopic, which is expressed in the inability to see green;
• tritanopic, when there is no sensitivity to blue.

When the ability to perceive colors is not absent at all, but only slightly reduced, they speak, accordingly, about such phenomena as:

• protanomaly;
• deuteranomaly;
• tritanomaly.

Clinically, absolute and partial color blindness is distinguished. The complete inability to see the spectrum is called achromatopsia... This violation is less common than others..

Indications for checking the color sensitivity of the eyes

As a rule, people suffering from such disorders apply for this.

1. Color weakness... A person looks at the image for a long time, since he has difficulty in describing some shades, and is often mistaken.
2. Absolute color blindness... People with this disorder only see the world in shades of black and white.
3. ... It develops in connection with destructive processes in the cerebral cortex, which often cause a violation different types sensitivity, including vision and hearing. People with such anomalies completely lose their ability to detect colors or cannot group similar shades.

The degree of violation of color sensitivity, as well as its features, ophthalmologists in most cases determine with the help. These are 27 card pages on which the drawing is applied in the form of colored spots and dots of equal brightness, but different shades. Depending on what kind of visual impairment a person suffers from, he can distinguish between individual images, and sees some pictures in monochrome.

How the test goes

In order for the results to give objective information, the test is carried out under the condition:

• normal general health and mood;
• the location of the picture at the same level with the eyes of the person being checked;
• looking at the picture for no more than 10 seconds.

Otherwise, the results will be unreliable.

Decoding tables

In order to convert the results of the check into a diagnosis, it is important to know what deviations a particular vision of each picture reveals. It should be borne in mind that only an ophthalmologist can decipher the results with accuracy, and the check will be as informative and accurate as possible when it is performed using paper rather than electronic media, because the settings of a particular computer can change the true test colors. So:

• card 1... On it is the number "96". The table does not carry a special diagnostic load, as it is intended more for clarification and familiarization with the test;

• card 2... A square and a triangle are distinguishable here. Those who do not see it are simulators;

• card 3... It has the number "9" on it. The color blind will say that it is "5";

• card 4... In this figure, a person with normal color vision sees a triangle, and in case of deviations, a circle;

• card 5... The number "13" is distinguishable. People with color blindness will claim to see "6";

• card 6... It has a circle and a triangular shape. A person who does not distinguish colors well will not see them;

• card 7... The number "9" should be seen by both people with normal and problematic color perception. Do not see? Simulators;

• card 8... The number "5" on it is visible only to the healthy;

• card 9... For those who do not distinguish shades of red, it will seem that in the picture "8" or "6". And only people with normal color vision will see the nine;

• card 10... Anyone who sees "68" in this picture, as well as "66" or "69", has problems with the perception of colors. A healthy person will find "136" here;

• card 11... The number "14" should be read here by both people with normal vision and with disabilities;
• card 12... The number "12" is seen here, but those suffering from a lack of perception of the red color will not see it;

• card 13... The picture shows a circle and a triangle. Those with green color problems will only find the triangle. If red is not perceived, only a circle will be visible;

• card 14... On it - the numbers "3", "6" and "0". If you are unable to distinguish between green, "1" and "6" will be visible. And if there are problems with red - "1", "0" and "6";

• card 15... Only healthy people can distinguish between a circle and a triangle with a square. Those who have trouble identifying colors will offer different answers;

• picture 16... On it is the number "96", which can be easily read by a person with normal vision. If there are difficulties with the red spectrum, then only nine will be visible. When the problem is green, the six will be noticeable;

• picture 17... The triangle and circle shown here will only be seen by the healthy. People with color vision impairment recognize only one of the shapes;

• picture 18... In this figure, a healthy person will make out squares of different colors, located in horizontal and vertical rows. With the wrong perception of colors, assumptions about the monochrome of some rows or columns arise;

• picture 19... On it is the number "95". A person with a color anomaly will only see "5";

• picture 20... The person being tested, who has a healthy color perception, will describe a circle and a triangle here. A color blind person will not see them.

As for pictures with # 21 to # 27, they are the same as described above.

Interpretation of results

It is based on the number of correct and incorrect answers from the point of view of a person with normal color sensitivity. When the check gives reason to suspect color blindness, another test is carried out, but with a set of cards to clarify the nature of the deviation.

Talitsy Rabkin is a simple and quick, accessible and informative method that allows you to diagnose the degree of color perception, but only if the testing is carried out according to the rules, and the ophthalmologist interprets the results.

Other ways to test eyesight for color perception

There is another way to identify or exclude visual anomalies in which a person does not correctly distinguish colors.

It is based on a description of the image in pictures that resemble Rabkin's cards. They consist of spots of different colors of similar brightness, where images are encrypted. Depending on what the person being tested was able to see, conclusions are drawn about the nature of the violation of his color perception.

It also consists in determining anomalies using tables and was developed by the author in 1949-1951. Prior to that, all diagnostic images were created through trial and fit. At the heart of Yustova's cards are scientific indicators about the characteristics of the sensitivity of the eye, which made it possible to determine by calculation the pairs of colors that color-blind people do not perceive.

FALANT research

It is used in rare cases, for example, when it comes to hiring a job with strict requirements regarding color vision. It allows not only to identify abnormalities of vision, but also to see how the ability of the eyes is influenced by factors such as:

• the degree of brightness;
• the duration of visual attention;
• atmospheric pressure and composition of the surrounding air;
• noise level;
• age and other parameters.

In the United States, for example, everyone who wants to join the military is sure to go through such a study.

The essence of the method is in determining the color that the beacon emits, installed at a certain distance from the checked one.

Its glow is made up of a combination of three main shades of the spectrum, slightly muffled by a special filter. People with color blindness are not able to accurately determine color, although there is evidence that a third of those suffering from mild visual impairment are successfully tested.

This is another way to identify color blindness and its characteristics. It consists in the fact that the person being tested is offered to lay out skeins of woolen threads, of different shades, in three primary colors. It would seem that there is nothing easier. So it is, if you do not take into account that there are 133 such balls. Based on the results, conclusions are drawn about the degree of color sensitivity of the eyes.

Stilling method

Its essence is in assessing the correctness of the description of colors in 64 pictures with different shapes and color fields.

Instrumental methods

These are methods of testing for color blindness using special equipment:

• spectroanomaloscope Rabkin
• instruments of Girinberg and Ebney;
• Nagel's anomaloscope.

It is based on mixing the pure colors of the spectrum to obtain and compare shades obtained in different ways. For example, the person being tested is asked to mix red with green in such a way that a shade of yellow is obtained, taken as a sample.

Occupational restrictions for color blindness

Unfortunately, blindness to colors and shades limits a person in his professional capabilities. Color blind people will not be able to become, for example:

• doctors and;
• the military, as well as civilian sailors and pilots.

This is because the inability to recognize colors endangers the life of the person himself, as well as those with whom he interacts by occupation. So, for example, immunity to traffic signals can lead to both minor accidents and large-scale ones, with the death of the driver, passengers and pedestrians.

Is color blindness treated?

Therapy for congenital color blindness is not possible. As for the acquired, he:

• corrected by surgery if cataract is the cause;
• can be corrected by wearing special optics, contact and non-contact.

Despite the fact that color blindness does not threaten health, it seriously impairs the quality of life.

Conclusion

Color vision testing has become a mandatory procedure in many cases. It is carried out in different ways, and the results sometimes deprive people of the opportunity to do what they love. Taking this into account, there are those who want to purchase a certificate without going through the examination. You should be aware that in such cases, the responsibility for the consequences rests entirely with the owner of the forged document, and if fraud is revealed, he can be brought to administrative responsibility and fined tens of thousands of rubles.

Video - Color Blindness Test