Where is color blindness most common?

Color blindness and color weakness

Color vision disorders: Disturbance of color perception (color inability), either in the form of a Color weakness or one Color blindness.

Around 8% of all men are congenitally unable to color, but only 0.5% of women. Most often, those affected suffer from a form of color weakness or color blindness for individual colors: they see one or more colors less strongly or not at all, the world of colors is mixed together for them from fewer colors than with normal sighted people. When the rare inherited complete color blindness (Achromatopsia), those affected can only distinguish between shades of gray. The color inefficiency is not a disease; however, it can have a significant impact on daily life, e.g. B. in choosing a career. Acquired color inefficiencies are also rare, in these cases the underlying cause such as an eye disease or a stroke must be investigated.

Leading complaints

  • Problems with color naming or differentiation
  • Yellow, blue or red vision (in the event of an overdose of certain drugs or poisoning)
  • Poor visual acuity, hypersensitivity to bright light (with complete color blindness)

Color perception in the case of color blindness: Top row: The color-healthy person perceives all colors. Second row: color spectrum of a red-blind man. Third row: color spectrum of a green-blind person. Fourth row: Color perception in the case of blue weakness. Fifth row: color spectrum of a color blind person.
ASM / ASL

When to the doctor

In the next few weeks if

  • You suspect that you or your child may have color weakness.

Immediately if

  • You suddenly see everything red or yellow or notice any other change in your color perception.

The illness

Disease emergence

The color-savvy man creates all other colors from the three spectral colors red, green and blue by mixing them. Three different retinal cell types (also called cones) are responsible for this. These color sensory cells are located in the center of the retina and only work in daylight. So at night "all cats are really gray".

In the case of a color sensory disorder, the interaction of the three color sense cell types is disturbed. The reason for this lies in the retina, in the optic nerve or in the brain itself.

Causes and Risk Factors

Hereditary color inefficiency is expressed either in color weakness or color blindness. In the case of color weakness, the eye is less sensitive to the corresponding color or to several colors due to a lack of visual pigment. With color blindness, the person affected no longer perceives one or more colors.

Complete color blindness is very rare, mostly there is partial color blindness in which one type of color-sensing cell is missing, e.g. B. red blindness (protanopia), green blindness (deuteranopia) or a mixture of both. Since those affected regularly mix up the two colors, all of these cases are called Red-green blindness. Fortunately, the failure of two (monochromatic) or even all three color sensations (complete color blindness) is very rare. In the complete color blindness, achromatopsia, none of the 3 cone types work. Those affected see everything in gray and also suffer from poor visual acuity and hypersensitivity to bright light.

Sudden color inefficiency. A sudden onset of color inefficiency is always a sign to be taken seriously. B. an optic nerve inflammation or a retinal disease. A stroke, a traumatic brain injury or another brain lesion can also disrupt the central processing of color vision. In this case it will be color blindness cerebral achromatopsia called. Color ineffectiveness as a side effect of medication (e.g. Resochin®, Cordarex®) or as a sign of poisoning, e.g. B. with thimble (digitalis).

Diagnostic assurance

Various color tests can confirm the diagnosis:

  • Pseudoisochromatic panels: This test shows numbers on a colored background that can only be recognized correctly by color-minded people. Only red / green faults are checked (see figure).
  • Farnsworth color stain method: The patient has to sort stones with different color gradations. This test is more complex, but it can also detect blue disturbances.
  • Nagel anomaloscope: This device can quantitatively detect the color weakness. The patient has to "mix" a given color with the help of a turning screw. The red-weak one is z. B. to set a given mixed color, need more red than the color standard and the value read on the anomaloscope (AQ value, anomalous quotient) is correspondingly lower. This enables precise information on the type of color ineffectiveness and its characteristics. For many professions, being red is not a problem, but red blindness is an exclusion criterion, e.g. B. with painters, bus drivers or pilots.

Acquired types of color ineffectiveness cannot be recorded well with the color tests. As a rule, the patient's description provides information about the unusual color perception.

treatment

The congenital forms color ineffectiveness cannot be dealt with at the moment. An explanation, e.g. B. in relation to the career choice must therefore be made early. For a number of years, however, in addition to other visual disorders, color inefficiencies have also been in the gene therapy sights of researchers. Experts expect the first procedures to be approved from 2018.

The very rare ones acquired species Depending on the illness, the responsible specialists (ophthalmologist, neurologist or internist) are asked for color inefficiency. If there is a suspicion of a drug overdose, the doctor will immediately check the preparations taken.

forecast

The innate color ineffectiveness cannot yet be cured, but it does not change in the course of life. In the case of acquired color inability, the prognosis depends on the underlying disease and its treatment. So z. B. Stroke-related inefficiencies in color may well regress over time.

Your pharmacy recommends

Most color unfit cope well with their poor eyesight. Nevertheless, a number of tools are offered, e.g. B .:

  • The Eyeborg transforms colors into sound waves, which the color unfit can hear through a loudspeaker in the ear as different tones.
  • For red-green blind people there are special glasses that filter out part of the red and green light so that the person affected can better distinguish between red and green.

Further information

At www.sehtestbilder.de you will find test images for color recognition.

Authors

Dr. rer. nat. Katharina Munk in: Health Today, edited by Dr. med. Arne Schäffler. Trias, Stuttgart, 3rd edition (2014). Revision and update of the sections "Symptoms and leading complaints", "The disease", "Treatment", "Prognosis", "Your pharmacy recommends" and "Further information: Dr. Sonja Kempinski | last changed on 10:38 am


Important note: This article has been written according to scientific standards and has been checked by medical professionals. The information communicated in this article can in no way replace professional advice in your pharmacy. The content cannot and must not be used to make independent diagnoses or to start therapy.