The diagnosis of color blindness , although relatively easy to detect, often goes unnoticed for many years and is only reflected by a casual exposure to an Ishihara test or a typical driver’s license test.

Although it may sound strange, this is what happens in a lot of cases: we don’t stop to think about how we see, we just do it and think that our color, for example, blue is the same as the one other people perceive.

Brief definition of color blindness

Color blindness is a disorder of genetic origin in which the person who suffers it does not have the same number of types of cones in his visual system or has them but they are altered.

This is because we do not have the necessary elements to capture the wave frequencies that make us catch the light in the form of different colors, which is due to the sensory cells called cones.

Although most people have three types of cones (one for red, one for green and one for blue) and even in some women four have been detected (although this is very unusual), those who are colour-blind will have either three when at least one of them is altered or less.

This means that we cannot capture the wave frequency necessary to capture certain colours , perceiving the stimulation under a different wave frequency. In this way, the subject will not be able to appreciate a colour and those linked to it, perceiving them as if they were others.

The different types of color blindness

Colour blindness can occur in different ways, depending on the type of pigments that are not available or are altered. Specifically, there are three main types of colour blindness, which are explained below .

1. Acromatism

This is a very rare condition. Achromatism or monochromatism appears when the subject does not possess any pigment or the cones in question are not functional at all. The vision in this case is based on the information extracted from the cells that capture the luminosity, the rods, being only in gray scale, black and white.

2. Dichromatism

Generally, when we think of someone with color blindness we tend to identify him/her with someone who suffers from dichromatism . This is understood as the type of colour blindness caused by the absence of one of the types of pigments, so that it is not possible to perceive either the colour in question or the colours associated with it (for example, if someone cannot see the colour red they will also have an altered perception of orange). In this case the wave frequency that allows the perception of the colour cannot be captured, so the pigment that captures the nearest wave frequency will perform its function, causing the colours to be confused.

Within dichromatism we can identify three basic typologies.

2.1. Protanopia

The subject cannot pick up the wave frequencies that allow the colour red, which has a long wave frequency, to be seen. The colour red tends to be seen as beige or grey, sometimes with greenish tones. If the slingshot frequency is very high, yellow is perceived.

2.2. Tritanopia

The least common type of dichromatism, affecting the perception of shortwave frequencies. The person suffering from tritanopia does not have the pigment corresponding to the colour blue, which is often confused with green. Also, yellows tend to look like red, violet or white.

2.3. Deuteranopia

This is the most common type of color blindness along with protanopia. In this case he lacks the green pigment, not being able to capture wave frequencies proper to that color (which would be medium wave frequencies). The green is not captured, being generally seen of a beige color. The perception of red also tends to be affected, having brownish tones.

3. Abnormal trichromatism

Abnormal trichromatism occurs when the person in question possesses the same three types of pigments as the majority of the population, but nevertheless at least one is altered and not functional . Although it is possible that if they have a slight non-functional colour perception, they need very intense stimulation to be able to capture it, and their vision is more likely to be similar to that of a dichromatist.

Within this type of color blindness we can find three subtypes depending on which of the pigments is not functional.

3.1. Protanomaly

In this case, the subject is able to perceive the colours green and blue normally, but red is not assimilated and grasped normally.

3.2. Tritanomaly

Blue is not captured correctly, being easy to confuse with others depending on the wave frequency that is captured. Red and green are picked up normally.

3.3. Deuteranomaly

The abnormality in this case is found in the green pigment, which cannot be completely perceived.