Among the senses that we have we could say that the most used by all and constantly is the sight, through it we can perceive everything that is around us, light, darkness, colors of various shades, but the truth is that this is not the reality for everyone, as there are people who have difficulty distinguishing some colors, and is the condition that is called Daltonism.
Before continuing, a curious fact about this condition, it was discovered and described by John Dalton, was an English botanist, chemist and physicist, who working with flowers detected his inability to distinguish colors, and in 1794 described in an article for the first time this disease that he himself suffered, and in his honor was called Daltonism. When he died in 1844, he donated his eyes to science so that they could continue studying this condition.
But what is color blindness, why does it occur, this and more in the development of this publication.
To understand how it happens we must understand how the human eye works, or at least have a notion about it. I can say that it is one of the most complex senses of our body, but at the same time interesting..
Our eyeball is basically a system of lenses that are aligned so that the light from outer space enters through the iris to the back, this is where the magic happens, in the retina, which are a specialized set of nerve cells, organized side by side, and have the function of converting the light that reaches them in an electrical impulse, to send it through the optic nerve to the brain and interpret, in order to form the image. The process is very complex, of course, but very interesting in my opinion.
In the retina we have Cones and Rods, both are the ones that perceive our vision, in the case of the rods they are in charge of night vision, and the cones, which are the ones I will focus on in this publication, allow us to distinguish between a range of colors and tonalities.
We have red, green and blue cones, which in combination give us the possibility of even having the ability to distinguish up to a variety of 8000 colors.
The cause of this condition is a genetic disorder that involves the production of a defective structure in one or more types of cones, which results in the failure of the cones to perform their function (distinguish colors) and hence there is difficulty in perceiving colors and their different shades, and there is a variety in the expression of this condition.
It should be noted that it is hereditary, that it has no cure, but it is clearly not a condition that greatly affects the life of the person who suffers from it. I particularly prefer to call it a condition rather than a disease.
The best thing is to be able to recognize it at an early age because it can mean a considerable improvement in the child's life. But it is not always so easy to perceive in the school period, especially because the teaching staff is not trained to do so. But if you notice that at some point the child has difficulty learning colors when playing, we will probably be in the presence of this condition.
As I mentioned before, we have cones that perceive three main colors, and for this reason the failure in one will mean the difficulty to recognize the color or shades or combinations of colors in which this particular type of cone participates. That is, we could have a variable range in the expression of this condition, and so we have the following classification of color blindness:
Achromatic: In this type, very rare, all cones have some defect (structural or functional) and do not meet are able to interpret the light with its different wavelengths, so the colors are not possible; Therefore can only perceive, black, white and grayscale.
Monochromatic: in this type of person, only one of the types of cones that exist works, therefore if only the green cones work, it will be that color and its shades that can be recognized, being very limited for the other colors.
Dichromatic: One of the cones is affected, so it will only perceive the combination of colors of the other two that are working, this is one of the most common.
Anomalous trichromatic: They have all three cones but they tend to see the color tones in an altered way. That is, all three types of cones function, but they see the shades differently than they actually do. This is also a fairly common type of color blindness presentation.
To detect this condition is used what is called Ishihara test created by Shinobu Ishihara, Japanese doctor, who in 1917 presented this test and it is the same that is still used to diagnose color blindness. Surely you have seen these primers who have submitted tests to obtain a driver's license, it is frequently used in that case.
Conclusion
I know that color blindness can bring with it some limitations in terms of performing some activities, for example, in the medical field of pathological anatomy, where different dyes are used to be able to see specific cells, it can certainly be a limitation, depending on the type of color blindness that the person presents, of course.
But in general a person with color blindness can lead a normal life, like any other person, even never realizing it and not being affected at all. Do you know anyone with this condition? Have you been left with knowledge after reading this publication?
Links consulted
This publication contributes 5% of beneficiary to the 
