Color blindness is one of the color vision disorders and can be congenital or acquired. Color vision disorders, sometimes called color sense disorders, include color vision deficiency and the various forms of color blindness. Congenital color blindness remains constant in its course and does not worsen. Acquired color vision disorders, however, can worsen in progression without treatment.
What is color blindness?
There are three types of color blindness. In achondroplasia, there is complete color blindness. Affected individuals can only see black and white and shades of gray. Partial color blindness, also called monochromasia, is when the affected person can only perceive one color. Dichromasia is also a partial color blindness. However, in this form, those affected confuse two colors with each other. Therefore, dichromasia is divided into three subgroups. Red blindness is when the color red cannot be perceived and is therefore confused with the color green. In green blindness, the affected person does not perceive the color green and confuses it with the color red. If blue blindness is present, the color blue cannot be perceived correctly and is therefore confused with the color yellow. Color blindness is usually congenital and is inherited in a sex-linked manner. The most common form is green blindness. Blue blindness and total color blindness are extremely rare.
Causes
Color blindness can be congenital or acquired. In most cases, it is a congenital condition. However, there are several diseases of the optic nerve or retina that can cause color blindness. Colors are detected with the help of very specific sensory cells called cones. There are three different types of cones, on which three different color pigments are located. The L cones perceive the color red, the M cones the color green and the S cones the color blue. By mixing these three basic colors, all visible hues are created in the brain. If the perception is disturbed in one or even all cones, color blindness occurs.
Symptoms, complaints and signs
The term color blindness is mainly used colloquially and actually refers to the inability to distinguish the colors red and green. Thus, the affected person is not generally blind to all colors, but predominantly to the two main colors. Other colors are perceived with a gray haze, but can be distinguished from each other. Symptomatically, it is noticeable that affected persons already have difficulties in childhood to distinguish red from green objects. The phenomenon usually occurs in children’s drawings, in which the child makes a color choice that seems irritating or creative to the adult. Upon closer examination, the inability in visual perception is usually revealed. The inability to distinguish colors from one another results in certain difficulties in everyday life, but these can usually be easily compensated for in other ways. For example, affected persons cannot distinguish an unripe strawberry from a ripe strawberry, so they need help in choosing. Color blindness has no effect on the ability of adults to drive, because traffic light phases can be detected on the basis of the sequence. Also with the selection of suitable clothes help is often necessary, a labeling of the colors in the closet or a color sorting creates improvement here. Color blindness is not a disease, does not lead to further deterioration of vision and is rather an anatomical feature. Most affected people cope well in everyday life.
Diagnosis and course
Color blindness can be diagnosed using two different methods. The first way is to check the color sense with the help of special color charts, the Ishihara charts. On these boards are various numbers composed of color spots. The background is also spotted, but in a different color. Numbers and background, however, have the same brightness. Patients with color blindness either do not recognize the numbers at all or recognize them incorrectly. By evaluating the results on the different panels, the doctor can determine which form of color blindness is present. The second option for diagnosis is the so-called anomaloscope.This is a type of tube through which the patient looks at a two-part test disc. In the lower part of the disc, a certain shade of yellow is displayed, the brightness of which can be changed. In the upper part of the test disc, the patient has to imitate the yellow tone shown by mixing red and green. Based on the mixing result by the patient, the physician can diagnose a specific form of color blindness. All congenital forms of color blindness remain constant in their progression. In color blindness, symptoms vary in severity depending on the cause. Most commonly, the visual disturbance occurs in the red-green range. Unfortunately, there is no effective therapy for congenital color blindness. In acquired forms, other diseases are causally responsible for the visual disorder. In most cases, these are diseases of the optic nerve or the retina. Depending on the causative disease, other visual functions may also be impaired.
Complications
Many different complications occur with color blindness. Usually, the patient can lead an ordinary life even with color blindness and is only barely affected in his or her functioning and activities. However, in the case of congenital color blindness, there is no known cure. In this case, the patient has to live with the symptom all his life. Complications can be primarily of a psychological nature and lead to reduced self-esteem. In some cases, it is not possible for the affected person to perform certain professions or to actively participate in road traffic. The risk of an accident is also somewhat increased due to color blindness. However, if accidents or other injuries do not occur, life expectancy is not reduced due to color blindness. Due to color blindness, some activities in everyday life are more difficult, but can be mastered with exercises. If color blindness occurs in the course of a disease, it can be improved or completely cured in some cases. However, the underlying disease is always treated first. Color blindness itself does not lead to any particular medical complications.
When should you see a doctor?
As a rule, color blindness does not require a visit to a doctor. The symptoms of color blindness do not worsen over time and, unfortunately, cannot be treated. However, if the disease is not congenital but acquired, a visit to the doctor may well be worthwhile to avoid further complications. The doctor must be consulted if the symptoms increase or if, in addition to color blindness, the patient’s vision also develops negatively. This can lead to various complaints, such as veil vision or even double vision. The examination and treatment of color blindness is usually performed by an ophthalmologist. In some cases, color blindness can be completely cured by diagnosing the underlying disease. However, these cases occur very rarely. In the case of visual impairment, a visual aid must continue to be worn at all times so as not to further promote this visual impairment. Especially with children, parents must pay attention to the correct wearing of visual aids. As a rule, this condition does not negatively affect or reduce the patient’s quality of life.
Treatment and therapy
If the color blindness or color vision disorder is congenital, there is no treatment method to cure it yet. If the cause is another disease, measures can be taken to treat them. In some cases, this also makes it possible to reduce or even cure color blindness.
Outlook and prognosis
The prognosis of color blindness is tied to the extent of impairment present as well as the cause of the disease. In the case of a congenital disorder of vision, no change in color blindness can be achieved despite modern medical therapies. The missing visual cells, which make color vision possible, were not created during the development process of the embryo for genetic reasons. If color blindness is acquired during life, further deterioration of visual acuity may develop. This is especially true for affected individuals who do not seek medical care.Depending on the extent of the impairment, wearing special glasses, using magnifying glasses or binoculars can improve vision. With optimal light exposure as well as the presence of two-color vision, alleviation of symptoms can be achieved. In individual cases, patients suffering from a neurological cause of color blindness have a chance of recovery. If the doctors succeed in finding the reason for the impairments in extensive examinations, there is a chance of recovery. If the cause can be treated or corrected by surgery, the patient has a good prognosis. After a few months of therapy, the usual vision may return. Similarly, spontaneous recovery may occur in patients of trauma or shock.
Prevention
Since color blindness is a congenital disease in the majority of cases, it is not possible to take preventive measures against the occurrence of the disease. The disease is inherited in a sex-dependent manner. Men are affected more frequently than women. Therefore, it makes sense to have an early diagnosis made if there is a hereditary predisposition for the occurrence of color blindness.
Follow-up
In the case of color blindness, the options for aftercare are extremely limited. Usually, this condition cannot be treated either, so affected individuals have to live with this complaint for the rest of their lives. Only in very rare cases can color blindness be treated or improved. Self-cure does not occur with this disease, although color blindness does not reduce the life expectancy of the affected person. The earlier the disease is recognized, the better the further course of this complaint. The affected persons are mostly dependent on the help of other people in their life due to this disease, so that they are not too strongly limited in their everyday life. In this context, the loving and caring support of one’s own family or friends has a very positive effect on the course of the disease. This can also prevent depression or other possible psychological upsets, which can have a negative impact on the quality of life of the person affected. Also the contact to other patients of color blindness can be useful. This often leads to an exchange of information, which can make everyday life much easier. If the color blindness is congenital, a genetic counseling is sometimes useful in case of an existing desire to have children.
What you can do yourself
In the retina of the eyes, there are three different cone-shaped photoreceptors in the area of sharpest vision, the macula, each of which is particularly sensitive to blue, green and red light. In the remaining area of the retina, there are mainly rod-shaped photoreceptors that perceive extremely weak light and are extremely sensitive to moving objects in the periphery. True color blindness, in which one or more types of cones for color vision fail completely due to genetic predispositions or other factors, must be distinguished from the more common color deficiency. Color deficiency is present when, for example, the cones for red or for green show reduced visual performance. There are no effective therapies for congenital color blindness (yet). Congenital color blindness does not change throughout life. If it is an acquired color blindness, the course depends on the causative factors. If these can be eliminated, no further visual deterioration is to be expected, but also no serious improvement, because failed photoreceptors cannot regenerate. Self-help measures include training that teaches how to interpret statements from secondary light information. For example, the illuminated red at a traffic light is always the top light, while the green light is always the bottom light. If the normal lighting on the rear of a car suddenly lights up brighter, this is the brake light.
