Color blindness in women
We are so used to seeing the world in all the diversity of its colors, that we do not even know how it can be otherwise. How can you see the green foliage brown or gray, and the ripe tomato dark green or saturated gray? It turns out you can. There is a small part of the population of the planet that sees the colors that are customary for us, completely different, sometimes even without realizing it. Such people are called colorblind, and they are mostly men. So is color blindness in women is a common fiction, and the disease in fact can be attributed to purely male pathologies, as the infamous haemophilia?
Is there color blindness in women?
No matter how weak the gender might want to consider yourself unaffected by this particular kind of visual impairment, like color blindness, they are directly related to it. And this does not prevent them from getting color blind in fact, 20 times less often than men.
Yes, the statistics in this case are more severe to the strong sex. Color blindness, although considered a rare pathology of vision, is diagnosed according to different data from 2 to 8 representatives of the stronger sex of 100. For women, this figure is much smaller: only 4 women of the weaker sex out of 1000 see the colors not as they really are.
But so far we have only used the generalized concept of pathology, which since 1794 is commonly called color blindness. And it all began with the fact that a physicist from England John Dalton at age 26 accidentally learned about a certain peculiarity of his vision. At one of the social parties where John was invited as a guest, it turned out that he does not distinguish between red and its shades. The same feature he found with his brothers, as he later told in his writings.
It was only about the lack of perception of red color and how the spectrum visible to man is distorted. It was this syndrome that acquired the name "color blindness". Subsequently, it was found that the violation of color perception can have different shades: a person may not perceive a certain color, and depending on this, his picture of the world in a certain spectrum will not coincide with the generally accepted one, or see the color in black and white. However, in the people, various violations of the perception of color are still called color-blindness.
In fact, the prevalence of various forms of color blindness differs both among men and women. The complete absence of color vision is extremely rare (1 person per million) and almost never occurs in women. But the violation of red-green eyes is typical for 5 women out of 1000 (for men this figure is much higher: 8 out of 100).
And yet, no matter how small the figure reflecting the incidence of color blindness in women, it says that the weak sex is also characteristic of the weak sex, but to a lesser extent than to the strong one.
Causes of the color blindness in women
When we talked about the fact that a woman has a direct connection with a visual impairment, diagnosed mainly in men, she did not blink a bit with her soul. And the point here is not in the peculiarities of men's vision in the presence of women, and not in violence against men by the weaker sex. The whole problem is in genetics. But let's not run ahead, but try to figure out why the bulk of people see the world in some colors, and a relatively small group - in others.
Our eye, like many other organs of the human body, is by no means a simple mechanism. It provides a unique opportunity not only to distinguish objects, but also to see them in color. Such a possibility gives us special nerve cells that can be found in the central part of the retina.
These unusual cells of the central nervous system are called color-sensitive receptors or cones. Such receptors in the eye should be 3 kinds, and each of them shows sensitivity to a light wave of a certain frequency. Each kind of cone contains a special pigment that is sensitive to a specific color: red, green or blue.
Perhaps the reader will have a legitimate question: how are the other colors that distinguish our eyes? Well, everything here is extremely simple, other colors and shades we see as a result of mixing of 3 primary colors. For example, to see the bark of trees as it is, it is enough to distinguish between red and green colors, and to see the eggplant purple you need to distinguish between blue and red hues. Yes, there to say, at school in drawing lessons, many experimented with watercolors, trying to get more and more colors, so that America will not have to open to anyone.
If we go further, we actually perceive as a color of a wave of a certain length. As a red color, we perceive a wave with a length of up to 570 nanometers, as blue - a wave no more than 443 nm, and the yellow color we attribute to waves up to 544 nm.
A person whose eyes perceive waves of different lengths, sees colors as they are to be distinguished. Such people are called trichomatous, which in translation from ancient Greek means "three colors".
With daltonism, events can develop in 3 directions:
- absence in the retina of the eye of one of the pigments,
- Reducing the effectiveness of red, blue or yellow pigment,
- color blindness or lack of basic pigments.
In principle, one can speak of a disease in the literal sense of the word only in the latter case. A lack or decrease in the effectiveness of the pigment is attributed rather to the characteristics of vision, because a person still remains able to distinguish colors, even if not in the generally accepted sense. In addition, these people often distinguish more shades than those who possess normal vision. Here it is not a disease, but a deviation from the norm. What causes such deviations can be understood by considering the mechanism of development of pathology.
Pathogenesis
At the heart of the pathogenesis of color blindness in women and men in most cases is the anomaly of the female chromosome, designated by the letter X. It is the X chromosome that is responsible for carrying the recessive trait, which, however, does not always manifest itself.
Let's remember from biology: the female sexual set of chromosomes consists of 2 chromosomes X, and the male has one chromosome X and Y. If a woman is an abnormal X-chromosome, she can pass a recessive sign to her children. Boys and girls have equal chances to get such a "gift" from their mother, but the probability of becoming color-blind in girls is much less.
The explanation is simple. The girl receives the X chromosome from her father and mother. If the mother gave her daughter the "wrong" chromosome (while she can have normal vision, being only a carrier of recessive information), the compensation mechanism is activated, that is, vision develops on the basis of the "right" paternal X chromosome. But the girl, like her mother, becomes the bearer of an abnormal gene, and therefore, can pass it on to her children.
If the "wrong" X chromosome is received by a boy, there is nothing to compensate for the recessive gene, because in its genome there is only one such chromosome. So, color blindness is more likely to be passed on to the son than the daughter.
For a woman to discover color blindness, it is necessary that she received a recessive gene from both her mother and her father. This is possible only if the father is diagnosed with color blindness, and the mother, at least, is the carrier of the abnormal chromosome. If only the father is sick and the mother does not have a tendency to violate the color perception, their daughter is not threatened, since the abnormal X chromosome obtained from the father does not appear in the presence of a dominant healthy X chromosome from the mother.
Since color blindness is considered a recessive sign, which in the presence of a dominant gene is rare, the prevalence of pathology remains small. The probability for a color-blind man to meet a woman with an abnormal X-chromosome is small, which means that the disease can threaten daughters only in exceptional cases.
But the boys in this regard, no luck. After all, they can receive color blindness as an inheritance from the mother even with a healthy father. Risk factors in this case again become carriage or illness of the mother, while the father's health does not affect the descendants-boys, because they can not get a recessive sign from the parent of their own sex.
So far we have spoken about the congenital pathology of vision. However, color blindness can also be acquired, in which case its symptoms do not always appear on an ongoing basis.
The reasons for acquired color blindness can be both physiological processes in the body, and the intake of certain drugs (in the latter case, the symptoms can be either constant or passing). To the physiological processes can be attributed to the aging of the body. The wear of the lens leads to its cloudiness (karakkontakte), which is manifested not only by deterioration of visual acuity, but also by a change in the perception of colors.
Another cause of color blindness in adulthood or childhood can be considered pathology associated with eye trauma if the process involved retina or optic nerve.
Symptoms of the color blindness in women
As we have already mentioned, color blindness can have different manifestations. People with normal vision with respect to colors and their designations have certain patterns, so we not only consider the leaves of the trees to be green, but we also see them as such.
Color-blinds do not have such patterns, because not all color-blinds see images of the surrounding world in the same way. The color scale, which a person sees with a violation of color perception, depends on whether the cone with which pigment is absent or less effective. In this regard, distinguish several types of color blindness, each of which is inherent only for them characteristic first signs and a certain gamut of colors and shades caught by the eye.
Dichromatia is a visual impairment, in which one of the primary colors falls out of the spectrum. Dichromates in the retina lack cones with one of the pigments: red, yellow or blue. These people can also be divided into 3 subgroups:
- about protanopic dichromatia (protanopia) is said in the absence of a red pigment,
- on deuteranopic dichromatia (deuteronopia) indicates the absence of a pigment responsible for the perception of green color,
- In the absence of blue pigment, they speak of tritanopic dichromate (tritanopia).
The states under which the weakening of any of the main pigments is observed is called an anomalous trichromation. They can also be divided into subgroups:
- protanomaliya - weakening the activity of the red pigment,
- deuteranomalia - a decrease in the effectiveness of green pigment,
- tritanomalia - low efficiency of pigment blue.
The absence of all 3 three pigments leads to a person seeing the world in black and white, which in fact can be called different shades of gray. Such a pathology is called complete color blindness or achromatopia.
One of the options achromatopii can be considered monochromasia, when a person is able to distinguish only one color and its shades. In this case, it makes no sense to talk about color vision, because on the basis of one color it is impossible to get other colors.
Achromatopia and its variety of monochromasia are extremely rare. Pathology affects mostly men. Most often, this pathology is accompanied by a different symptom: a violation of visual acuity and nystagmus (involuntary movement of the pupils).
If one of the pigments is missing or weakened, they speak of partial color blindness, which is also characteristic of the female sex. The most common is the weakening of the red and green pigment (or both). For example, 3-4 women from 1000 suffer from deuteronomy, and other violations of perception of the red-green spectrum are noted by only 0.1% of women. In the latter case, the vision remains color, but the color perception is even more distorted.
Violation of the perception of blue color is a rare type of vision pathology, which, by the way, does not have sexual preferences, since it is associated with distortions of genes in chromosome 7. Both tritanopia and tritanomalia are found in 1 woman out of 100. The same statistics is also found in men.
For acquired color blindness, there are problems with distinguishing between yellow and blue colors. In this case, the dependence on the sex of the patient is also not traced.
Complications and consequences
So, color blindness is nothing but a violation of the perception of a certain part of the color spectrum, which leaves its imprint on what colors the person sees the world around. The most surprising thing is that color blinds most often do not suspect anything of their defect. Since childhood, all children are taught to call colors in certain words: red, green, yellow, etc. Baby colorblinders will, like everyone else, say that the leaves on the tree are green, even if in fact they see them in a different color, and it is this color in the child's mind that will be considered green.
This feature of color blindness often does not allow diagnosing pathology at an early age. And only chance can force a person (or people close to him) to think about how accurate his vision is in determining colors. Although, in principle, it is often not so important when a disease is found, if it does not progress during life and has the same manifestations at any stage.
But on the other hand, color blindness can be an unexpected obstacle to the goal, if a young man or a girl from childhood dreams of becoming a pilot or a doctor. After all, if in childhood color blindness does not cause any inconvenience (after all, the child sees the world exactly from birth, and there is nothing to compare it with), then in adulthood, when it comes to choosing a profession, the disease makes certain, not always pleasant adjustments.
So color-blind do not fit the profession, where great importance is attached not only to visual acuity, but also to correct perception of color. Accurate vision should have drivers, pilots, doctors, machinists, sailors, because the way a person of such a profession is oriented in a situation, often the life of other people depends. Color blindness can be an obstacle even for obtaining a driving license that grants the right to drive a private car, not to mention public transport.
The most common species of color blindness are the distorted perception of red and green. However, it is these colors that are commonly used as signal colors. It is the inability to adequately respond to signals and becomes an obstacle in professional activity and even in everyday life (for example, when crossing a road with a traffic light having only 2 colors, color blinds can be lost).
Color blindness in women is unlikely to affect their happiness in marriage, but problems in their professional activities and communication with other people can pursue them no less than men. The different color perception of people with normal vision and color blindness can lead to curious situations, as a result of which the latter can become a target for ridicule and jokes.
Inaccessible for Dalit women and some creative professions, such as a painter, photographer (unless it's a black and white shooting), a designer (no matter what has to be designed: landscape, interior or clothing, color perception in any case plays an important role). Now many young women go to the police on a par with men. Alas, color-blind workers do not do such a job.
Diagnostics of the color blindness in women
For the ophthalmologist, the sex of the patient who came to the doctor does not matter, therefore, the diagnosis of color blindness in women is the same as in men with the same methods. People whose work requires perfect vision are tested for color perception regularly as part of a medical examination with an ophthalmologist.
Verification of color perception can be carried out using three popular methods: spectral, electrophysiological and using pseudo-isochromatic tables (pigmented).
The spectral method involves the use of special apparatuses. Such devices include the device Ebni, the spectral anomaloscopes Nagel and Rabkin, which were developed in different periods of the XX century. In the work of this apparatus, the Rayleigh color equation is used.
The application of the pigment method is carried out using polychromatic tables, which at different times were developed by many scientists (Stilling, Ishiyar, Schaff, Fletcher together with Gamblin, Felgagen, Rabkin). Instead of tables, you can use an Edridge-Green lantern with light filters, a non-spectral anomaloscope by Demkina, the same device perfected by Rautian in 1950, and other similar instruments for studying color perception.
In our clinics, the most popular tables were the famous ophthalmologist Efim Borisovich Rabkin, the first edition of which was published in 1936, and the ninth in 1971. Rabkin developed his method for the full study of human color perception, which contains 27 basic and auxiliary tables (control, for the study of color vision in childhood, the definition of color thresholds, the rapidity of color discrimination).
Each of the main or control tables consists of points having different sizes and colors. With normal vision, a person on these tables can see certain numbers and geometric shapes. People with broken color perception either do not see the picture at all, or they see the picture in a distorted manner, as a result they can call quite different figures and figures, describe only the individual parts of the bitmap that is on the table.
Rubkin's tables are accompanied by a technique for using them, written by the author of the tables and published in 1971. Depending on what the patients see on the tables, you can draw an accurate conclusion about the variety of color blindness.
Tables show patients one by one, placing them in a vertical plane at the eye level of the patient. A series of tables are shown from a distance of half a meter-meter from 5 to 10 minutes (for studying each table only 5-7 seconds are given, in the case of an uncertain response, the show is repeated). The lighting should be within 400-500 lux (natural light or fluorescent lights that do not distort the color spectrum).
Diagnosis is performed for each eye separately. The doctor at the same time fills a special card for each patient, which makes notes on each table (plus, minus or question mark).
Using 27 basic tables, Rubkin allows you to determine with great accuracy the type and degree of color blindness, but the cause of the pathology remains hidden from the eye of the doctor. Auxiliary tables help to clarify the nuances of human visual perception (for example, visual acuity, reaction speed, etc.).
Differential diagnosis
Differential diagnosis is conducted between a congenital pathology of color perception and a disorder caused by the use of a certain group of medications or eye diseases (cataracts, glaucoma, eye injuries with damage to the optic nerve or retina). Also, it plays a big role for the expertise of professionalism and the ability to serve in the troops.
Electrophysiological method is used to study the features of color perception in various pathologies. So the chromatic perimetry is indicated if there are suspicions of the pathology of the optic nerve or central visual pathways, which are equally capable of causing color blindness in both men and women. Electroretinography is a method that allows to determine color blindness by the functional state of pigmented cones in the structure of the eye.
Treatment of the color blindness in women
Since in most cases, color blindness in women develops due to eye diseases, it is primarily necessary to treat these diseases. Restoration of the normal functioning of the affected eye will lead to the normalization of color perception. Sometimes for these purposes it is necessary to resort to an operative intervention, as, for example, with cataracts.
If the cause of color blindness was the use of medications, then there is no particular concern in this regard. Usually, this phenomenon disappears after the medication with such a side effect is discontinued. However, at the time of taking the drug still have to beware of crossing the road at the crossroads and especially the railway tracks.
To cure congenital (hereditary) color blindness in women and men is not yet possible for medicine. But this does not mean that scientists do not pay due attention to this issue. Simply drug treatment in case of violation of color perception is irrelevant, and other methods are either considered insufficiently ineffective, or are under development.
For example, the use of genetic engineering techniques may, in the future, help solve the problem of color blindness by introducing the missing color-sensitive receptor cells into the retina of the eye. But so far this method has not been used in humans, although experiments on monkeys have shown good results.
Attempts are made to correct color vision with lenses using a metal called neodymium. Glasses, whose lenses are covered with a thin layer of neodymium, help to better distinguish colors for patients who have a reduced perception of red or green. However, wearing such glasses in other types of color blindness has no significant results. In addition, special lenses slightly distort the picture and reduce visual acuity.
In America, recently conducted studies on multi-layered glasses, which again include neodymium. It can be hoped that soon color blinds will have the opportunity to see a picture of the world as seen by people with normal vision. And while adjust their color perception and adapt in life they will help such advice:
- Color perception in people with reduced sensitivity to colors improves in the absence of bright light, so you can try wearing glasses with wide rims or protective shields on either side of the lens.
- For those who have almost no color vision, it is recommended to use darkened eyeglasses, which additionally have side shields. Dull light improves the performance of sensitive cones.
- In the end, you can learn to live with your pathology, focusing not on color, but on the location of objects and the reaction of other people to them. Some nuances, such as traffic light signals, can simply be learned without delving into the coloring of individual alarms, but simply remembering their location.
Many people live without experiencing much discomfort due to a violation of the perception of flowers, until they focus their attention. Normally, you can live on if you do not focus on your daltonism, and compensate for the lack of color perception with memory and attention.
Prevention
Since color blindness in women and men can be congenital, and the blame for everything is a recessive gene transmitted from generation to generation along the "mother-son" line, then effective prevention is not said in this case. Color blindness or distorted color perception is just a physiologically conditioned sign that rarely appears in the presence of a dominant trichomatia gene (normal vision). And it's not easy to fight with what is inherent in nature itself.
The only thing that can be done is to be examined by future parents before conception of the child on the features of color perception, for example, using the same tables of Rubkin, which can be found even on the Internet. In this case, a woman and a man can foresee in advance what the probability of the birth of their children with normal vision.
But even if it turns out that a child can find color blindness, this is not a reason to part or refuse to have a child. It is important to examine the child at the age of 3-4 years, when he will begin to distinguish colors, and hence his color perception can be checked using the tables of Rabkin for children.
If it is found that the child does not correctly perceive certain colors, it is necessary to provide him with special attention and training, which will help the child to navigate the world without reliance on the color of objects. The most important points that ensure the child's safety (the same traffic light signals) will simply have to be learned together with the baby.
Forecast
Color blindness in women, caused by eye pathologies, can be prevented if you carefully and carefully treat your eyesight, treat eye diseases in a timely manner, and avoid injury. The prognosis in this case depends on the severity of the pathology and the effectiveness of its treatment, but in most cases it is favorable.
Medical expert editor
Portnov Alexey Alexandrovich
Education: Kiev National Medical University. A.A. Bogomolets, Specialty - "General Medicine"
Other articles on the topic
Color blindness is a special type of visual impairment, which is manifested in the absence of perception of certain colors, most often green, red and purple. Basically, color blinds are not able to distinguish a particular color or several colors.
