Surely everyone has heard of such a vision feature as color blindness, or daltonism. This is a fairly common phenomenon, which affects every one in 12 men and every one in 200 women. With daltonism, people have difficulty distinguishing or do not distinguish certain colors at all, or even all colors. Hence the name – “color blindness”. However, few people know that there is a vision feature opposite to daltonism, in which people see 10 times more colors. This extremely rare phenomenon is called tetrachromacy.
Some people see 10 times more colors than everyone else. Source: iflscience.com
How many colors do people with tetrachromacy see
We have previously discussed how people's ability to see colors can vary slightly. For example, most students can see ultraviolet, which is a color that most people cannot see. However, all people without any vision problems see about one million shades on average.
Tetrachromats are significantly superior to ordinary people in this regard, as they can see about 100 million shades. They are especially sensitive to orange shades. Therefore, if you look at the world through the eyes of such people, it will be brighter and more colorful.
People with tetrachromacy see about 10 million shades. Source: elitplus-clinic.ru
Why do some people see 10 times more colors?
The human eye contains two types of light-sensitive receptors – rods and cones. Rods are responsible for black and white vision and are distinguished by a higher light sensitivity. Cones have a lower light sensitivity, but they allow us to distinguish colors.
An ordinary person has three cones in the eye. In the case of color blindness, due to a certain mutation, the eyes contain only two cones. This is why people with color blindness have a reduced ability to distinguish colors. Surely you have already guessed that tetrachromacy is also a mutation that leads to an increase in the number of cones in the eye. People with this vision feature have four cones.
Cones inside our eyes (special light-sensitive receptors) allow us to distinguish colors. Source: elitplus-clinic.ru
True, the extra cone itself does not provide humans with this unique ability. For this, it must have a “frequency setting” different from the other three cones. But that’s not all — vision must have a fourth color channel, through which additional color information is transmitted to the brain. This allows the brain to process expanded information about colors.
Perhaps this is why people with tetrachromacy are much less common than with color blindness. For the latter, as has already been said above, it is enough to simply lose one of the cones, and not to acquire a number of additional abilities. According to some data, up to 12% of people in the world have a mutation associated with tetrachromacy. However, according to a 2010 study published in the Journal of Vision, only one person out of 24 carriers of the corresponding genetic variant have “tetrachromatic vision.”
How is tetrachromacy diagnosed
Unlike color blindness, tetrachromacy is very poorly studied. Scientists still do not know exactly how widespread this phenomenon is and how it affects vision. Presumably, people with mild tetrachromacy distinguish shades slightly better than the average person. If a person has severe tetrachromacy, he sees the world in shades that other people do not see.
Artist Concetta Antico only learned in adulthood that she had tetrachromacy. Photo source: factroom.ru
However, the problem is that people who have this “superpower” usually don’t even know about it. They simply don’t know how other people see the world, since they have no way to look at it through the eyes of another person. A striking example of this is the story of artist Concetta Antico, who for a long time didn’t know that she had a unique ability.
The woman taught drawing and often asked her students if they saw this or that shade. The students, instead of telling her the truth, simply nodded their heads. Only years later did she learn that in fact no one but her saw those shades, and in general she saw the world differently than everyone else. This is exactly the case when the phrase: “I'm an artist, this is how I see it,” can be taken literally.
But is it possible to diagnose this vision feature? Unfortunately, there is currently no reliable testing method. DNA testing is usually used to identify the mutation that causes tetrachromacy. However, as we have found out, having a mutation does not guarantee the presence of special vision abilities. To identify them, special technologies are required.
Even people with normal vision see the same colors differently. Source: tengrinews.kz
Finally, we note that even ordinary people who have three cones in their eyes may perceive colors differently. This feature can be compared with smartphone displays – they may have different color temperatures and other parameters visible to the eye, while the main characteristics of the matrices will be the same. The thing is that color reproduction depends not only on the hardware, but also on the software.
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Exactly the same situation is with our vision – the colors we see depend not only on the eyes, but also on the brain, which processes and interprets the information received. If you want to see this for yourself, just look at how color perception depends on context. This is just one of many examples of how the brain influences color perception.