Acquired color blindness can occur onlyon the eye, which struck the retina or optic nerve. His is the progressive deterioration over time, and the difficulty in distinguishing between blue and yellow.
Inherited color blindness is more common, affects both eyes, and does not degrade over time. This embodiment of color blindness in varying degrees of severity is present in 8% of men and 0.4% of women.
Hereditary blindness is associated with the X-chromosome and is almost always passed from mother - the carrier of the gene to her son.
One type of pigment is sensitive to red, the other - to the green, and the third - to the blue. More precisely, they are sensitive to the wavelength corresponding to red, green and blue colors in our understanding.
In humans, the daily peak sensitivity of these pigments (maximum spectral sensitivity of the eye) are in the 555 nm wavelength for red, 530 nm for green and 426 nm for blue.
The vision of all the colors of the world is provided by "folding" of these three colors in our brain.
People with normal color vision have cones in all three pigment (red, green and blue) are called trichromats (from the word "Chromos" - color).
If you distinguish only two colors, then you will be called dichromate. This means that one of the pigments in the retina have not.
Men who have no red pigment -it protanopicheskie dichromates, and those who lack the green pigment - deyteranopicheskie dichromates (commonly called red "Protos" (Greek -. first), and the green color called "deyteros" (Greek -. second), combining the names of colors with the word "Anop" (no view), formed the word "Protanopia" and "deuteranopia" to describe tsvetoslepoty on red and green).
There are also people who have all three pigments in cones available, but the activity of one of the pigments is reduced. These people - abnormal trichromats.
Defect red pigment found in conesmore often. According to statistics, 8% of white men and 0.4% of white women have red-green color vision defect, three quarters of them - abnormal trichromats.
People with defective blue pigment in the cones are extremely rare, as well as people who have completely no color vision, ie when one badly sees all three colors.
Variations in color perception in humans is notsuggest that the person is not healthy. We can only say that the person has its own color perception of the surrounding world, different from the color perception of other people.
History has taught us many times that all ingenious people perceive the world around them, and the nature of the phenomenon is not so, like everyone else. It is to them we owe the new discoveries and inventions.
Tsvetoslepye one color and people with reducedpaint color vision perceive the world around them differently than we do, but often do not notice their differences from others. Do not overlook it sometimes surrounding. After all, these people are learning from childhood called colored everyday objects generally accepted symbols. They hear and remember that the grass - green, sky - blue, blood - red. Furthermore, they retain the ability to distinguish between colors in the degree Grace.
Blindness to red-green color is transmitted bysuccession. Because the cause of this or that kind tsvetoslepoty - a molecular defects in the genes responsible for the synthesis of color-sensitive pigments. Currently we identified all genes encoded pigments which are responsible for each color.
To get an answer to the question of whether the children inherit color blindness, the woman should contact the genetic counseling. There she was asked to take the test.
There are many methods of genetictest: study of family history, the study of color vision in the intended carrier of the mutant gene using precision instruments, etc. Most modern - genetic testing methods, allowing for the analysis of DNA, to identify the mutant gene and to clarify the nature of the defect in a protein molecule, which is the cause of the eye disease..
If a woman would be a carrier of the gene and tsvetoslepoty decide not to give birth to a boy, she would be able to conduct an ultrasound or genetic testing to determine the sex of the baby in utero.
Only in cases where a hereditarydisease threatens the life of the patient and the hereditary defect associated with only a single gene, you can resort to replacement of the defective protein in the gene. This is the perfect method for targeted treatment of color defects is used only for some diseases.