Colour blindness
El colorblindness is inability of a person to see certain colors In its normal form. There are different types, but the most common is one that causes deficiency to distinguish red and green tones.
This condition is hereditary, although in the adulthood can be presented by consequence of diseases like glaucoma, Alzheimer and parkinson.
Colour blindness
El colorblindness is inability of a person to see certain colors In its normal form. There are different types, but the most common is one that causes deficiency to distinguish red and green tones.
This condition is hereditary, although in the adulthood can be presented by consequence of diseases like glaucoma, Alzheimer and parkinson.
What is color blindness and who can suffer it?
It is the condition that causes a person to have inability to distinguish certain colors In its normal form. This disease owes its name to the English scientist John Dalton, who had the first discovered case of color blindness.
This condition can affect people's vision differently, so there are different types, in fact, it is believed that no colorblind looks the same as another. Color blindness is a genetic disorder and its hereditary factor is linked to sex, since the gene that is abnormal is in one of the two sex chromosomes.
The disease is the product of a recessive gene associated with the X chromosomeTherefore, those men who inherit the X chromosome together with the defective gene will suffer from this pathology.
In women, this condition is uncommon, because in order to have it it is necessary that both sex chromosomes have the recessive gene, so both parents would have to be colorblind. For this reason there are so few colorblind women in the world.
We will talk colorblindness when it comes from a hereditary genetic origin while we will talk about dyschromatipsia when its origin don't be hereditary. In general, in medicine the term dyschromatopsia is used to describe any problem related to color perception (hereditary, acquired ...).
Symptoms of color blindness
The symptoms vary in each person, but usually the condition manifests in the following way:
- Inability to see colors and their brightness in a normal way
- Inability to distinguish shadows of one color or differentiate similar colors.
- The symptoms of this condition can occur in such a mild way that many people suffering from this disease they are unaware that they are colorblind.
- Many parents recognize that their child is colorblind when they begin to show you the name of the colors.
- People with severe color blindness usually present involuntary eye movements.
Causes
The retina has two types of cells: rods and cones. The rods are used to detect light and dark, the cones allow to detect the colors and they are in the center of the vision. There are three types of cones:
- The cones that detect the color red.
- The cones that detect the color green.
- The cones that detect the blue color.
When we look at an object, the brain uses the information sent by the cone cells to distinguish and differentiate the colors in an image. Color blindness occurs when there is absence of one or more cones cells, when these do not work correctly or when they present an inability to distinguish a tone in its normal form.
Types of color blindness
At present we can distinguish three types of color blindness, let's know each one:
Dichromatism
It is the most common and affects the cones responsible for distinguishing red and green tones. When one of the cell types is absent, the other receives all the stimuli, which is why in most cases both visual stimuli are captured as a single color.
People who suffer from dicromatism have an inability to see the colors green and red. However, this condition has a variant that occurs when the cones responsible for capturing the blue color are absent. People who have this type of disorder they confuse the blue tones with the yellows.
In this way, the three types of dichromatisms we find are:
- La protanopia it is the absence of photoreceptor cells in the retina that perceive the color red.
- Deuteranopia it is the absence of the photoreceptor cells of the retina that perceive the green color.
- Tritanopia it is the absence of the photoreceptor cells of the retina that perceive the color blue.
Anomalous tricomatrism
This type occurs when the person has the three cones, but these have some kind of deficiency that prevents them from functioning correctly.
The symptoms of trichomatrism are similar to those of dichromatism, but this form is much milder.
achromatopsia
La achromatopsia is most serious type of color blindness, who suffer it can only differentiate ranges of colors in the gray scale.
Tests to detect it
there are different tests to diagnose color blindness and its degree of complexity, however, this condition is often detected in the childhood stage by parents or teachers during elementary school.
The most common diagnostic test is the Ishihara test We explain below.
Treatment of color blindness
This visual disorder does not represent any type of health risk and those who suffer from it can lead their lives normally, in fact, most people adapt to this condition without any problem.
Color blindness It has no cure or treatment. There are currently glasses and glasses especially designed so that the colorblind person can differentiate colors better. These accessories are like a kind of filter which is placed in contact lenses or glasses.
Ishihara test
This test owes its name to its creator, Dr. Shinobu Ishihara. The test consists of 38 circular templates that have points of different colors and sizes drawn. The points on each card form a number that is perceived in one way by people with normal vision and another by the person with color blindness.
Usually, color blind people who undergo this test they will not be able to observe the number, they will see different numbers or they will simply not see anything. Although the test has 38 cards, it is enough for a person to see only a few to be diagnosed.