Color blindness can significantly ruin a person's life. This is a genetic damage to the eye that does not affect visual acuity in any way. There are many myths and rumors associated with it. How is the test for color blindness and what methods of testing vision exist, read in our article.
Myth 1
Colorblind people see everything in black and white or do not distinguish between red and green.
This is not entirely true. There are quite a few types of color blindness, they are associated with the absence of a pigment in the retina that can distinguish certain colors.
Sometimes these pigments are not enough, a person distinguishes all colors, but they look muted, in pastel colors.
With another type of color blindness, the world before the eyes of a person looks like in an old photograph in which blue or green dye was added during printing.
As compensation, color blind people are able to distinguish many more shades that appear the same to the normal eye.
Myth 2
Only men are colorblind.
This is also not entirely true. About 5% of people on Earth suffer from some degree of color blindness. And among them every tenth is a woman. This is a hereditary condition, if there were people with such a problem in the family, it can be transmitted even after several generations.
The pathological gene is associated with the X chromosome and is passed from mother to son. If in the family the father is color-blind, and the mother is a carrier of the gene, then the pathology can also be revealed in the daughter. Color blindness in a girl can also appear if the paternal grandmother was the carrier of the pathological gene. Since most often only one X chromosome is damaged, women have a spare, healthy one.
Most cases of color blindness are detected by people by chance, during medical examinations.
Myth 3
This is a congenital condition, it is impossible to get sick with it.
Under certain circumstances, the retina of the eye is injured, the pigment ceases to be produced in it, because of this, the person ceases to distinguish colors. Men and women are equally susceptible to this disorder. It can even happen to a child.
Sometimes, with a retinal injury, color blindness develops in only one eye, the other remains with normal vision.
Temporary color blindness occurs when taking certain medications. If you do not pay attention to this, it can permanently damage the retina and develop into a permanent one.
Partial deterioration sometimes occurs with age, the process is slow, the person does not notice the changes.
Myth 4
All dogs are color blind and see the world in black and white.
The latest research has shown that dogs are guided by color and its intensity and brightness.
It is impossible to determine color blindness by the appearance of the eye - it looks exactly the same as a healthy one. The peculiarity of vision is often paid attention to in childhood, when the child constantly confuses colors, cannot identify the same ones, and so on. In many cases, this has no consequences.
Reasons for the appearance
There are several causes of color blindness.
It is congenital and acquired. Congenital affects mainly boys.
Acquired arises also for many reasons.
- cataract
With this disease, the lens becomes cloudy, light cannot pass through the cones normally, and color perception is disturbed. In this case, only one eye can be problematic, the other remains healthy.
- malfunction of cones
the pigment is located in the cones themselves, if their work is disturbed, it is produced incorrectly.
- eye injury
With a minor injury, color blindness is temporary and does not need treatment. The eye needs only rest. In more complex cases, treatment is required, which will be prescribed by an ophthalmologist. The eye needs complete rest.
- tumors
A growing tumor acts on the nerve endings of the eye. This disrupts the passage of the impulse, color perception is disturbed. Any tumor should be removed, after surgery treatment is carried out.
- CNS diseases
If color blindness is associated with this problem, it should be treated by a neurologist along with an ophthalmologist. If the cause of the disease is identified and eliminated, color blindness will pass.
- Parkinson's disease and stroke
With these diseases, the passage of nerve impulses from the brain to the eye, to photoreceptor cells is blocked, due to which color perception is lost.
- diabetes
- Taking medication
If such a problem arises, you need to inform your doctor, it may be possible to change medications, find their analogues.
Acquired color blindness can be present in both eyes, most often it is uneven, it can even be of various types.
Color blind people and professions
In many cases, color blindness does not affect a person's choice of profession. But there are those where the ability to perfectly distinguish colors plays a key role. For example, drivers, machinists, pilots. They should not be engaged in medicine, it is unlikely that they will succeed in the field of interior design or fashion.
It will also be difficult for them in teaching, especially with children - in many cases it is necessary to distinguish colors.
In general, all professions where you need to be able to distinguish colors, shades and halftones.
It is for this that various tests are carried out to detect deviations in the ability to distinguish colors.
Checking for color blindness in children
A small child with a color vision disorder does not realize that he sees the world a little differently than other people, for him his vision is natural. It makes no sense to diagnose him before 3 years. You can suspect something is wrong by indirect signs - if the child does not always reach for the brightest toy, but can take a gray and pale one.
Usually children memorize the names of colors by the age of 3-4. Find objects of the same color even earlier. But if the baby has color blindness, he is physically unable to do this. Parents are angry with him, but the child does not understand the reason.
Most often, the child does not distinguish between red and green, blue and yellow.
If a child has such a feature of vision, then first of all you need to calm down. First of all, parents - color blindness is not a disease, the child just has to adapt to such vision, and parents have to come to terms with this feature of the child.
Parents can check their eyesight for color blindness even before the child enters school quite simply - by watching how he paints pictures.
If he often mixes up the color of the grass or the sky, in his drawings they are unnatural, this can be an alarming sign.
Older children are given several single-color sheets of colored paper and asked to choose the same color. If the baby is at a loss, you should definitely consult an ophthalmologist.
For older preschoolers and younger students, you can already use the same tests as for adults.
Pupils
For schoolchildren, this problem can cause many difficulties in learning. What is written on the board with colored chalk is often invisible and indistinguishable for him. And their own drawings differ in unnatural colors. Teachers should be aware of this feature of their student, help him cope with circumstances beyond his control - for example, he should sit in the classroom so as not to see light reflections on the blackboard.
If, before school, you did not encounter a similar problem for your child, then primary school is the time to do it.
For adults, there are other diagnostic methods.
Diagnostic methods
There are many types of color blindness. The easiest is the inability to distinguish between shades of color. For example, deep pink is perceived as red, while lighter tones are seen as white.
Rabkin's tables
The most famous and popular diagnostics is using Rabkin's tables. They depict a lot of multi-colored circles of different shapes and sizes. All these circles are of the same brightness, and among them numbers or geometric shapes stand out in a different color.
A person with normal vision can almost easily distinguish them from the rest. If there are violations, these encrypted figures will be indistinguishable for him.
Testing
It happens simply - signs are placed in front of the subject in good uniform lighting, the patient examines them for several seconds and says what he sees. In this case, the person should be in a relaxed state and feel good. It takes 7-10 seconds to look at one picture, the pictures are located at a distance of 1 meter from the eyes at the same level with them.
In these tables there are also figures-traps. For example, a person with normal color perception sees 9, and a color-blind person sees 5, or a circle. They are seen only by color blind people with a certain type of color blindness, the doctor will be able to determine from his tables what kind of pigment is missing on the retina.
Several pictures in the set were created to identify simulators, those who, for some reason, want to deceive the tablets when passing the test. These plates depict pictures that are clearly and clearly distinguishable with normal vision and with any form of color blindness. The doctor can easily determine which color the patient does not distinguish.
The circles on the tables are selected in such a way as to check all possible deviations. And the color combinations in them are not random. However, when passing the test in a healthy person, errors are possible - the result may depend on the screen of the computer itself and on the lighting.
There are 48 plates in the set, 27 are used for general diagnostics. The rest are needed for a deeper analysis. They are necessarily included in the examinations of professional drivers, machinists, pilots.
The main tables of Rabkin can be bought, the rest remain for a more detailed analysis from the doctor. It is useless for a color blind person to simulate healthy vision, the doctor will decipher it anyway. It is also useless to pretend to be colorblind at military commissions - the remaining plates will still show color perception, it is impossible to learn them.
If these charts show a severe color impairment, such as red and green looking the same, the person will be denied a license altogether. The same will happen if there is no color discrimination in the blue-yellow range.
Checking for color blindness using the Rabkin table is used all over the world, it gives the most reliable result, type and degree of pathology. And control pictures will clarify the diagnosis.
Yustova's technique
This technique also consists of cards and is designed to identify which particular color violation is present in the patient.
The subject is offered four sets of cards, each of them reveals the pathology of one primary color.
- The first set reveals violations in the perception of red and its shades,
- the second is the green spectrum
- the third is blue
- fourth - black and white text
The tables are special pictures with "broken" squares, which depict a stylized letter C, with a gap in one of the sides of the square. The subject must determine the location of the break.
There are 12 tables of the test, each table shows several pictures with such an image. All cells form one tone, the test is constructed in such a way that the possibility of its “memorization” is excluded.
The test is also good because it is easy to conduct with children who do not yet know numbers and geometric shapes.
Such a test is also popular among ophthalmologists in the world. It is also used in the diagnosis of acquired color blindness in adults after various injuries, diseases and taking certain medications.
Ishkhara test
The test is somewhat reminiscent of Rabkin's tables. In it, the subject is also offered tables consisting of many circles of different colors and sizes. But in it a person should no longer distinguish numbers or letters, but pictures and simple images.
Such a test is mainly used to diagnose color blindness in children, they like such pictures and they willingly guess encrypted images. These pictures can also be offered to those who "learned" Rabkin's tables for "passing a medical examination." If color blindness is present, a person will not be able to distinguish the desired image.
Some other tests for determining color blindness work in much the same way. These are the color schemes of Stilling, Schaaf, and some others. Their principle is about the same.
Special cases
There are special cases when checking vision for color blindness. When more in-depth studies are required, and the subjects are subject to increased requirements for the ability to distinguish colors.
Correct perception of colors is necessary not only for drivers of any transport. There are times when this can be key.
Military
When passing the military commission, such a test will be carried out. With normal visual acuity, they will still be drafted into the army, but you can serve in a very limited number of troops. In any case, it will not be possible to deceive the military registration and enlistment office,
Doctors
All physicians require full color perception. The health of other people depends on this, so doctors regularly check these parameters of their vision.
Chemists
If it is difficult to distinguish colors, then you can get very chemically. Many solutions outwardly differ only in shade, and the properties of the substances are different. It is better for a color blind person not to do chemistry professionally.
Treatment of color blindness
How to help a color blind person see the world in all its fullness of colors? After all, this is especially offensive if the loss of the ability to distinguish colors is acquired as a result of an accident.
Congenital
Now it is impossible to cure congenital, genetically determined color blindness. In order to somehow help a person, multi-colored lenses are specially selected for his vision. But this method is ineffective, controversial. It can even be dangerous for general vision. So while research is being done, and such contact lenses are not used.
Special glasses with multi-colored lenses have been created, but these are experimental models, they operate in certain lighting conditions and cannot be worn for a long time.
Attempts are also being made to introduce the missing genes into the retina of the eye - so far only with the help of computer programs on virtual color blind people. But research in this area is ongoing and, perhaps, a solution to the problem will still be found.
Acquired
Acquired color blindness can be cured. Treatment depends on what caused it.
- If medications were the cause, they must be canceled, color perception will be restored over time.
- Operably - by eliminating cataracts or other damage to the retina
Most often, when acquired color blindness occurs, visual acuity begins to fall in a person.
Drug treatment is prescribed by a doctor, you cannot prescribe it to yourself - this can result in an irreversible change in vision, which will only worsen, until a complete loss of color perception.
Ophthalmologists believe that about 8 percent of the male population of the planet and only 0.5 percent of women suffer from a disease such as color blindness. This disease is a violation of color perception by a person, as a result of which he also has the name of color blindness. Often the most important factor that affects its appearance is heredity. Due to the prevalence of color blindness, it is very important to understand why they test for this disease, how exactly it works, and what its results can mean.
Why is color blindness tested?
The human eye in its structure is a rather complex organ of the body, the retina of which takes part in the transformation of the light stimulus. Light-sensitive cones are located directly in this part of the visual system.
Their purpose is to sense the color spectrum in three ranges: red, green and blue. When some kind of disturbance occurs in this part of the eye, a person may no longer distinguish these colors from each other. Such a pathology is essentially color blindness.
How a color blind person sees
It is worth noting that the disease can be both congenital and acquired. That is why ophthalmologists advise from time to time to be examined for at least a minimum number of tests. This can be done quite easily during a periodic medical examination in any clinic or other medical institution.
Color blindness does not actually significantly affect human health, but at the same time, this disease can worsen the quality of life. First of all, this affects the ability to work in certain positions, as well as to acquire certain professions.
Ophthalmologists prohibit people with such a diagnosis from becoming military personnel, vehicle drivers, and medical workers.
On the video - checking for color blindness:
In turn, this situation can provoke an accident, which can lead to injury. They can be both fairly mild and serious, resulting in death. Similar situations also apply to people working in the military sphere or in any enterprises in which dangerous items are indicated by certain colors.
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How is the color blind test done in the hospital and at home
The process of passing a person's test for color blindness takes place in an ophthalmological office, which is equipped with appropriate polychromatic tables. They are colored numbers, letters and shapes. The main condition for this is that the patient must be with his back to the light source. This applies not only to the lamp, but also to the window. It is also worth paying attention to what is worth doing.
Rabkin test
Correct passing of the test implies the correct location of the table in front of the person. It should be in an upright position at a distance of one meter from the patient's eyes. It is worth noting that placing screens with images on a horizontal surface or at an angle can somehow affect the results of the vision test.
Each person should have no more than 7 seconds to think about their answer. His state of health at the same time should be completely normal. This refers to the absence of symptoms such as headaches, weakness, fatigue, depression, stress, etc. All of them can in one way or another affect the patient's ability to adequately analyze what he has seen.
How to check vision for color perception - Ryabkin's test: tables and pictures
In order to test yourself for color blindness, Rabkin's tables are widely used.
It consists of several dozen different pictures, where you can see images made up of circles of a certain diameter and shade. Depending on the severity of the pathology, as well as its type, the patient may or may not see certain numbers and figures. It will also be useful to know how it happens and what reviews exist.
On the video - Rabkin's test:
Types of color blindness - protanopia, tritanopia and deutranopia
The Rabkin test, if performed correctly, allows you to determine several different types of color blindness.
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Among them, ophthalmologists distinguish the following:
- - the visual system in this case cannot normally recognize the red spectrum;
- tritanopia- the retina with its cones is immune to blue-violet hues;
- deutranopia– the eye cannot see the green color spectrum.
Patients can be tested regardless of their age. Often, young children are not suitable for diagnosis due to the fact that they cannot clearly name either the numbers or the figures that are shown on the plates. There are currently no contraindications to undergoing an examination for the detection of color blindness. Find out if there are contraindications for computerized perimetry and what this examination will give.
Interpretation of results
In order to clearly understand how exactly a person passed the test for color blindness, you need to understand how you can decipher and interpret the results of his answers.
- The first element of Rabkin's table shows the number "96". This card is used by ophthalmologists to explain to each patient in what specific way it is necessary to be tested. But how are they used and what are the reviews about such lenses.
- The next part combines two geometric shapes- square and triangle. The purpose of this card is to identify the simulation.
Rabkin's tables: a square and a triangle are shown
- In the third part, a healthy patient can see the number "9". In the case when he has some pathological qualities regarding the perception of color, then his eye will determine only the number "5".
- The fourth table of the chromatic table contains again- the same image of a geometric figure. A healthy person with normal vision will see a triangle on it. The one who has a pathology in the form of color blindness is a circle.
Rabkin's tables: an image of a geometric figure
- In the fifth part there is an image of the number "13". In the case when the patient suffers from color blindness, he will be able to see only the number "6".
- On this card there are two shapes from geometry- triangle and circle. If a person has vision problems, then he will not be able to determine what is depicted.
- This card is designed to identify the simulation. This is due to the fact that the image of the number "9" on it will be seen by all people, regardless of their retinal color perception.
Rabkin's tables image 9
- In this part of the test, the number "5" is drawn.". Only those with good eyesight can see it.
- Healthy people on this card will see the number "9". All the rest, depending on the severity of the violation of the perception of the red spectrum, I can see either "6" or "8".
- On the tenth card, a healthy person will be able to see a three-digit number - “136". If there are any violations, it will be possible to make out only two numbers - “68”, “66” or “69”.
Rabkin's tables with the number 136
- In this part of the test, a snag is also hidden, which lies in the fact that both healthy and sick people can see the image. It is easy to see the number "14" on the card.
- In fact, on this element of the Rabkin table, it is quite easy to see the number "12" in the case when the eye perceives the red spectrum well. In the presence of a diagnosis, it will not be possible to consider the depicted drawings.
- This table depicts two geometric shapes- circle and triangle. This part of the test allows you to determine the presence of normal perception of green spectrum patients. In the case when pathology exists, a person can only see a triangle. Also, this card detects problems with seeing red. Such patients distinguish only the image of a circle.
Rabkin's tables in the form of a circle and a triangle
- This part of the test hides three numbers - "3", "6" and "0". Some of them are seen by people with poor perception of the green spectrum, some - with the indistinguishability of the red. In the first case, the patient will see "1" and "6", and in the second - "1", "0" and "6".
- On this card, unlike many others, three geometric shapes are encrypted. A healthy eye is able to see a circle, a square and a triangle. Pathology may be indicated by the perception of any other images.
Rabkin's tables in the form of three geometric figures
- In this part of testing, the number "96" is located on the card. When a person has a poor perception of red, he will see only the first digit, when green - the second.
- This card was created in such a way that a person with anomalies of the visual system could see only one of the geometric shapes depicted - either a circle or a triangle.
- This part of the test is significantly different from all the previous ones. This is due to the fact that a healthy person with normal vision on the card will be able to see rows and columns of squares with different colors. Any pathology of color perception leads to the fact that the patient will be able to distinguish only monophonic figures of a certain shade.
- This test table depicts the two-digit number "25". When diagnosing color blindness, a person will be able to see only one number "5".
- This part of the survey also has its own characteristics. A person with color perception problems will not be able to see absolutely nothing in the picture. With normal vision, geometric shapes in the form of a circle and a triangle will be distinguished.
Thus, a complete test for color blindness implies the passage of patients in all parts of the tables. But often it is enough just to determine what exactly is shown in several figures. The process itself can take from one minute to several. During this time, an ophthalmologist can fully assess the state of perception of colors of various spectra by a person's eyes.
There are also 7 more tables that are not included in the above list, but all of them are almost identical to the pictures described.
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In ophthalmic practice, color perception disorders are usually diagnosed using pseudo-isochromatic tables. One of these tests is the Rabkin table. The table consists of circles of different colors, which are arranged so that they form geometric shapes or numbers. With a violation of color perception, a person sees hidden numbers, those that are not visible during normal color perception.
The Rabkin table test must be taken in daylight, images are shown in random order with an exposure time of 5 seconds. The distance to the images should be about 0.5-1.0 meters.
This test is of particular importance for drivers of all types of transport (auto, water, rail), pilots, future artists, workers in the chemical and textile industries, etc.
How to take the test
- Calm down and relax.
- Make sure that the eyes and the picture in question are at the same level.
- Look at the picture for no more than 5 seconds.
- After recognizing / not recognizing the image in the picture, click on it.
- Read the description of the picture and compare with your result (if the text does not appear, your browser may be outdated - update it).
- Don't panic if your results don't match the description of the picture. When passing tests on-line, everything may depend on the matrix or color of the monitor. Be sure to see a specialist to dispel doubts.
- Find the “tell friends” button at the bottom of the page and click it (you need to monitor your vision).
Rabkin's polychromatic table for checking color perception (color blindness test).
 In the picture, the numbers 9, 6 or 96 are seen by both people with normal vision and people with manifestations of color blindness. It is intended to illustrate the meaning of the proposed test, in addition, this picture will help to identify cases of simulation. |
 On this sample, both normally seeing people and color blind people are able to distinguish between a triangle and a square. This image is also used to demonstrate the test and reveal the simulation. |
 People with normal vision see the number 9 in the picture. People with blindness in the green or red part of the spectrum (protanopia and deuteranopia) see the number 5. |
 Normally seeing people in this picture will see a triangle. People with color blindness in the green or red parts of the spectrum (protanopia, deuteranopia) see a circle. |
 Normally seeing people distinguish here the numbers 1, 3 or 13. People with color blindness in the green or red parts of the spectrum (protanopia, deuteranopia) see the number 6. |
 People with normal vision distinguish between the circle and the triangle depicted in this picture. With color blindness in the green or red parts of the spectrum (protanopia, deuteranopia), these geometric shapes are indistinguishable. |
 The number 9 in this picture is visible to both people with normal vision and people with manifestations of color blindness. |
 The number 5 shown in this picture is quite distinguishable, both for people with normal vision and for people with color blindness in the green or red parts of the spectrum (protanopia, deuteranopia), although the latter can hardly do it or not at all. |
 People with normal vision and color blind people in the green part of the spectrum (deuteranopes) see the number 9 shown here. Color blind people in the red part of the spectrum (protanopes) distinguish the numbers 6 or 8 in the picture. |
 The numbers 1, 3, 6 or 136 shown in the picture are visible to people with normal vision. Color-blind people in the green or red parts of the spectrum (protanopes, deuteranopes) are able to distinguish here the numbers 66, 68 or 69. |
 This image encodes the number 14, which can be distinguished by both people with normal vision and people with any manifestations of color blindness. |
 Normally seeing people, like color-blind people in the green part of the spectrum (deutronopes), see the image of the numbers 1, 2 or 12 in this picture. Color-blind people in the red part of the spectrum (protanopes) do not distinguish between these numbers. |
 Normally seeing people distinguish between a triangle and a circle in this picture. Color-blind people in the red part of the spectrum (protanopes) will see only a circle here, and color-blind people in the green part of the spectrum (deuteranopes) will see only a triangle. |
 People with normal vision distinguish in the picture, in its upper part, the numbers 3, 0 or 30, but in the lower part they see nothing. Color-blind people in the red part of the spectrum (protanopes) will see the numbers 1, 0 or 10 above, and the hidden number 6 below. Color-blind people in the green part of the spectrum (deuteranopes) will distinguish the number 1 from above and 6 below. |
 Normally seeing people distinguish between a circle (on the left) and a triangle (on the right) in this picture, and in its lower part they cannot distinguish anything. Colorblind people in the red part of the spectrum (protanopes) will see 2 triangles at the top and a square at the bottom. Color-blind people in the green part of the spectrum (deuteranopes) distinguish a triangle at the top left, and a square at the bottom. |
 People with normal vision in this picture see the numbers 9, 6 or 96. Color blind people in the red part of the spectrum (protanopes) distinguish only the number 9. Color blind people in the green part of the spectrum (deuteranopes) can only distinguish 6. |
 Normally seeing people distinguish between a triangle and a circle in the picture. Colorblind people in the red part of the spectrum (protanopes) see only a triangle. Color-blind people in the green part of the spectrum (deuteranopes) see only a circle. |
 People with normal vision see multi-colored vertical rows and single-color horizontal rows in this picture. Color-blind people in the red part of the spectrum (protanopes) will see the vertical 3rd, 5th, 7th rows as one-color, horizontal ones, too, as one-color. Color-blind people in the green part of the spectrum (deuteranopes) can perceive vertical rows 1, 2, 4, 6, 8 in one color and horizontal rows in multi-color. |
 Normally seeing people are able to distinguish here the numbers 2, 5 or 25. Color blind people in the green or red parts of the spectrum (protanopes, deuteranopes) will only distinguish the number 5. |
 People with normal vision will see a circle and a triangle in this picture. Color-blind people in the green or red parts of the spectrum (protanopes, deuteranopes) do not see these figures. |
 Normally seeing people, like color blind people in the red part of the spectrum (protanopes), are able to distinguish the numbers 9, 6 or 96 here. Color blind people in the green part of the spectrum (deuteranopes) see only 6 in the picture. |
 The number 5 shown in the picture is quite distinguishable for people with normal vision and for color blind people in the green or red parts of the spectrum (protanopes and deuteranopes), although for the latter it is quite difficult or impossible at all. |
 People with normal vision see the vertical rows in the picture in one color, and the horizontal rows in different colors. Color-blind people in the green or red parts of the spectrum (protanopes, deuteranopes) see multi-colored vertical rows, and horizontal rows - one-color. |
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They call the reduced ability or absolute inability of people to distinguish the colors of the spectrum, accessible to 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 kind of nerve cells, called cones for their shape. 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 - helps to see blue colors.
People who normally perceive the entire spectrum are called trichromats. They have a standard set of pigments that are present in the optimal amount.
Origin
Color blindness is of the following types.
- congenital i.e. inherited.
- Acquired which may develop due to:
- damage to the retina or optic nerve;
- aging of the body, provoking development, contributing to a decrease in visual acuity and worsening color perception;
- taking a number of medications.
Classify such color vision problems. Dichromacy, in which a person distinguishes two of the three primary colors. She 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, respectively, of such phenomena as:
- protanomaly;
- deuteranomaly;
- tritanomaly.
Clinically, absolute and partial color blindness are distinguished. The complete inability to see the spectrum is called achromatopsia. This disorder is less common than others..
Indications for checking the color susceptibility of the eyes
As a rule, people suffering from such disorders apply for this.
- color weakness. A person looks at the image for a long time, as he has difficulty in describing some shades, and often makes mistakes.
- Absolute color blindness. People with this disorder see the world only in shades of black and white.
- . It develops in connection with destructive processes in the cerebral cortex, which often cause a violation of various types of sensitivity, including vision and hearing. People with such anomalies completely lose the ability to identify colors or cannot group similar shades.
The degree of violation of color sensitivity, as well as its features, ophthalmologists in most cases determine using. 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, he can distinguish between individual images, and sees some pictures as monochrome.
How is the test
In order for the results to give objective information, the test is carried out under the condition:
- normal general well-being and mood;
- location of the picture on 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.
Table decoding
In order to convert the test results 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 accurately decipher the results, and the test 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. It has the number "96" on it. The table does not carry a special diagnostic load, since it is intended more for explanation and familiarization with the test;
- card 2. A square and a triangle are distinguishable here. Those who do not see this are simulators;
- card 3. It has the number "9" on it. The colorblind will say it's "5";
- card 4. In this figure, a person with normal color vision sees a triangle, and with deviations, a circle;
- card 5. The number "13" is distinguishable. Those suffering from color blindness will claim that they see "6";
- card 6. On it is a circle and a triangular figure. 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 healthy people;
- card 9. For those who do not distinguish between shades of red, it will seem that in the figure "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 those with deviations;
- card 12. The number "12" is visible here, but those suffering from the non-perception of red will not see this;
- card 13. The picture shows a circle and a triangle. Those who have problems with green will only detect a triangle. If red is not perceived, only a circle will be visible;
- card 14. On it are the numbers "3", "6" and "0". With the inability to distinguish 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 here. Those who have problems identifying colors will offer other answers;
- picture 16. On it is the number "96", which is easily read by a person with normal vision. If there are difficulties with the red spectrum, then only nine will be visible. When there is a problem with green, a six will be noticeable;
- picture 17. The triangle and circle shown here will only be seen by healthy people. People with impaired color perception recognize only one of the figures;
- picture 18. In this picture, a healthy person will see squares of different colors arranged in horizontal and vertical rows. With incorrect perception of colors, there are assumptions about the monochrome of some rows or columns;
- picture 19. It has the number 95 on it. A person with a color anomaly will only see "5";
- picture 20. The test subject, who has a healthy perception of colors, will describe a circle and a triangle here. A colorblind person will not see them.
As for the pictures from #21 to #27, they repeat those 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 test gives reason to suspect color blindness, another test is performed, but with a set of cards that allow you to clarify the nature of the deviation.
Rabkin's tables are a simple and fast, 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 gives the interpretation of the results.
Other ways to check vision for color perception
It is possible to identify or exclude visual anomalies in which a person incorrectly distinguishes colors in another way.
It is based on a description of the image in the pictures, reminiscent of Rabkin's cards. They consist of spots of different colors of similar brightness, where images are encrypted. Depending on what the person being checked managed 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 this, all diagnostic pictures were created through trials and fitting. Yustova's cards are based on scientific indicators about the characteristics of the sensitivity of the eye, which made it possible to determine by calculation pairs of colors that color-blind people do not perceive.
FALANT study
It is used in rare cases, for example, when it comes to hiring with strict requirements regarding color vision. It allows not only to identify visual anomalies, but also to see how factors such as:
- degree of brightness;
- 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 enlist in the military must undergo such a study.
The essence of the method is to determine the color emitted by a beacon installed at a certain distance from the one being tested.
Its glow is made up of a combination of the three main shades of the spectrum, slightly muffled by a special filter. People with color blindness are not able to accurately determine the color, although there is evidence that a third of those suffering from a mild form of visual impairment successfully pass the study.
This is another way to identify color blindness and its features. It consists in the fact that the person being checked is offered to lay out skeins of woolen threads of different shades according to the 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 tangles. Based on the results, conclusions are drawn about the degree of color sensitivity of the eyes.
Stilling method
Its essence is to assess the correctness of the description of colors in 64 pictures with different shapes and color fields.
Instrumental Methods
These are the methods of testing for color blindness using special equipment:
- spectroanomaloscope Rabkin
- instruments of Girinberg and Abney;
- Nagel anomaloscope.
It is based on mixing the pure colors of the spectrum to obtain and compare shades obtained in different ways. So, for example, the testee is asked to mix red with green in such a way that a shade of yellow is obtained, taken as a sample.
Occupational limitations for color blindness
Unfortunately, blindness to colors and shades limits a person in his professional capabilities. Colorblind people will not be able to become, for example:
- doctors and;
- military, as well as civilian sailors and pilots.
This is explained by the fact that the inability to recognize colors endangers the life of the person himself, as well as those with whom he interacts in the course of his activity. 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 there a cure for color blindness?
Therapy for congenital color blindness is not possible. As for the acquired, he:
- corrected surgically if the cause is a cataract;
- 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 by different methods, and the results sometimes deprive people of the opportunity to do what they love. With this in mind, there are those who wish to acquire a certificate without passing the examination. You should be aware that in such cases, the responsibility for the consequences lies entirely with the owner of the false document, and if fraud is detected, he can be held administratively liable and fined tens of thousands of rubles.
Video - Test for color blindness
Tables for checking color blindness
(taken from the book by E.B. Rabkin "Polychromatic tables for checking color perception).
Table 1 . All normal trichromats, anomalous trichromats and dichromats distinguish the numbers 9 and 6 equally correctly in the table (96). The table is intended primarily for demonstration of the method and for control purposes.
Table 2 .
All normal trichromats, anomalous trichromats and dichromats distinguish two figures equally correctly in the table: a square and a triangle. Like the first table, it is intended primarily for demonstration of the method and for control purposes.
Table 3. Normal trichromats distinguish the number 9 in the table.
Protanopes and deuteranopes distinguish the number 5.
Table 4.
Normal trichromats are distinguished in the triangle table.
Protanopes and deuteranopes see a circle.
Table 5.
Normal trichromats are distinguished in the table by the numbers 1 and 3 (13).
Protanopes and deuteranopes read this number as 6.
Table 6.
Normal trichromats distinguish two figures in the table:
circle and triangle.
Protanopes and deuteranopes do not distinguish between these figures.
Table 7.
Normal trichromats and protanopes
distinguish two numbers in the table - 9 and 6.
Deuteranopes can only recognize the number 6.
Table 8.
Normal trichromats distinguish the number 5 in the table.
Protanopes and deuteranopes distinguish this figure with difficulty, or do not distinguish it at all.
Table 9.
Normal trichromats and deuteranopes distinguish the number 9 in the table. Protanopes read it as 6 or 8.
Table 10.
Normal trichromats are distinguished in the table by the numbers 1, 3 and 6 (136). Protanopes and deuteranopes read two digits 66, 68 or 69 instead.
Table 11.
Normal trichromats distinguish between a circle and a triangle in the table. Protanopes distinguish a triangle-nick in the table, and deuteranopes - a circle,
or circle and triangle.
Table 12.
Normal trichromats and deuteranopes
distinguish in the table the numbers 1 and 2 (12).
Protanopes do not distinguish between these numbers.
Table 13.
Normal trichromats read a circle and a triangle in the table.
Protanopes distinguish only a circle, and deuteranopes a triangle.
Table 14
. Normal trichromats distinguish the numbers 3 and 0 (30) in the upper part of the table, and they do not distinguish anything in the lower part.
Protanopes read the numbers 1 and 0 (10) at the top of the table,
and at the bottom - a hidden number 6.
Deuteranopes distinguish the number 1 in the upper part of the table,
and at the bottom - a hidden number 6.
Table 15.
Normal trichromats distinguish two figures in the upper part of the table: a circle on the left and a triangle on the right.
Protanopes distinguish two triangles in the upper part of the table
and at the bottom is a square,
and deuteranopes - a triangle at the top left, and a square at the bottom.
Table 16.
in the table numbers 9 and 6 (96).
Protanopes distinguish it has only one number 9, deuteranopes- only the number 6.
Table 17. Normal trichromats are distinguished two figures: triangle and circle. Protanopes are distinguished in table triangle, and deuteranopes- circle.
Table 18.
Normal trichromats perceive available in the table horizontal rows of eight squares in each (color rows 9th, 10th, 11th, 12th, 13th, 14th 15th and 16th) as one-color;
the vertical rows perceived them as colorful.
Dichromats, on the other hand, perceive vertical rows as one color,
and protanopes accept
as single color vertical color rows—
3rd, 5th and 7th,
and deuteranopes - vertical color rows—
1st, 2nd, 4th, 6th and 8th.
Colored squares arranged horizontally are perceived by protanopes and deuteranopes as multi-colored.
Table 19.
table numbers 9 and 5 (95).
Protanopes and deuteranopes can only distinguish the number 5.
Table 20
.
Normal trichromats distinguish between a circle and a triangle in the table. Protanopes and deuteranopes of these figures do not distinguish.
Table 21.
Normal trichromats distinguish the vertical rows of six squares in the table V each (color rows No. 1, 2, 3, 4, 5, 6) as one-color; horizontal rows (No. 7, 8, 9, 10, 11, 12) are perceived as multi-colored. Dichromats, on the other hand, perceive vertical rows as multi-colored,
and horizontal - as one-color.
Table 22.
Normal trichromats are distinguished in table two numbers - 66.
Protanopes and deuteranopes correctly distinguish only one of these numbers.
Table 23.
distinguish the number 36 in the table.
these numbers do not distinguish.
Table 24.
Normal trichromats, protanopes and deu-teranopes
distinguish the number 14 in the table.
Persons with severe acquired pathology of color vision
these figures are not distinguished.
Table 25.
Normal trichromats, protanopes and deu-teranopes
distinguish the number 9 in the table.
Persons with severe acquired pathology of color vision
this figure is not distinguished.
Table 26.
Normal trichromats, protanopes and deu-teranopes
distinguish the number 4 in the table.
Persons with severe acquired pathology of color vision
this number is not recognized.
Table 27.
Normal trichromats distinguish the number 13 in the table.
Protanopes and deuteranopes do not distinguish this figure.
Thus, normal trichromats read correctly all twenty-seven tables, protanopes - seven to eight tables ( I, II, VII, XXIII, XXIV, XXV and XXVI ),
and deuteranopes are nine tables ( I, II, VIII, IX, XII, XXIII, XXIV, XXV and XXVI).
