Have you ever thought about the fact that people can see the world differently? Not in terms of their judgment or opinions, half-full or half-empty glass, but in the literal sense of the word. For some people the apple is red, but for others the apple is green. And it's not about psychology at all. Today we are going to talk about color blindness.
Color-blind people are those who cannot distinguish certain colors. Most often it is red and green, less often blue and yellow, but there are also those who cannot see colors at all. This diagnosis is called color blindness or complete color blindness. The only thing that helps these people navigate in space is intensity. The world looks like a black and white movie through their eyes.
How It All Works
There are nerve cells in the center of the retina called cones. There are three types of them, each one is responsible for the perception of a particular pigment: red, green, or blue. The combination of these pigments allows us to perceive the entire spectrum of colors and see the world in color. If some pigment is missing or insufficient, our visual perception is significantly altered.
An Unexpected Discovery
The first person to describe color blindness was the English scientist John Dalton, who was a deuteranope and did not distinguish green colors. Light green, for example, seemed dark red to him. In the 18th century, no one knew about the existence of visual defects in the perception of colors. The scientist thought he was just confusing the names of the colors. But once during a botany class he noticed that the flower was sky-blue in the sunlight and dark red in the candlelight. His brother had the same thing. Then Dalton realized that his eyesight was impaired and it was hereditary.
“The part of the picture that others call red seems to me like a shadow or merely poorly lit. Orange, green, and yellow seem like shades of the same color, from intense yellow to pale yellow,” John Dalton described in his work Unusual Cases of Color Perception.
What Is the Reason?
In most cases, color blindness is a hereditary problem. Male color blindness is more common than female color blindness. The thing is, the genes responsible for the frequent forms of color blindness are located in the X chromosome. Women have two of these chromosomes, so the defect in one of them is compensated by the other. Whereas men have only one X chromosome. When a male color-blind child is born, his daughters will be a carrier of the gene. They will be color blind only if the mother's X chromosome also carries this gene. As a result, 2% to 8% of men and only 0.8% of women suffer from color blindness. However, color perception problems may be acquired too, but only if a person has suffered physical or chemical damage to the eye, optic nerve, or brain. Deterioration in color perception can change with age or when taking medication.
Color blindness can be detected with a test of Japanese ophthalmologist Ishihara. During this test, you have to sit at a distance of 80 cm and place the pictures at eye level to be able to pass the test. An important condition is that you should not spend more than 5 seconds on one picture. No need to try to stare into infinity. This is not about abstraction. Once you've decided what's depicted in the circle, you click on it. The answers will vary, depending on whether you have a visual impairment or not. The result is not a diagnosis. The monitor may be distorting colors. If the result is not satisfactory, you should consult a specialist.
World through the Eyes of a Color-Blind Person
Daltonism comes in different forms. If a person is missing one visual pigment, they can only distinguish between two primary colors. Such people are called dichromats. Depending on the color abnormalities specialists differ: protanomaly, deuteranomaly and tritanomaly. In the first case, the pigment responsible for the red color is missing. In the second case, it is green. In the third one, it is blue. The efficiency of one of the pigments may simply be reduced, which doctors call an abnormal trichromatism. The easiest way to understand how color-blind people look at things is to use photos that have been altered to match their individual perceptions. There is actually an app called Daltonizer that shows how color-blind people see the world compared to normal people.
People with impaired red and green pigment are more common, even more common are those with reduced pigment indicators, but not with a complete lack of it. Complete color blindness is extremely rare. The chances are only increased in the case of a close family relationship. For example, there is a known case that took place on a small island, where the population was actively married to close relatives and 23 out of 1600 inhabitants suffered from complete color blindness.
Apart from the inconveniences related to everyday life and society (traffic lights, choice of fresh food, restrictions in choosing a profession), people with color blindness have certain advantages. According to the research by British scientist Tom Simonite, people who have difficulty distinguishing between red or green colors can distinguish many other shades. For example, swamp green is not just khaki to them. They see plenty of shades that other people don't perceive at all.
Attitude towards Problem
Color blindness cannot be cured, but it can be alleviated, for example, by using special lenses for people with red and green perception disorders. They can help you cope with too bright light. There are also special lenses for eyeglasses with neodymium glass. This is a special mineral glass that contains neodymium oxide or a mixture of rare earth oxides. The lenses are nicknamed “chameleon glass” for their features.
In 2009, an experiment on the treatment of color blindness using genetic engineering was conducted. The Nature journal published an article about missing genes being implanted into the retina of monkeys (these animals are naturally color blind). The experiment confirmed that it is not necessary to rebuild the entire nervous system in order to achieve good vision – it is sufficient to add a new receptor protein to the retina. Similar experiments were conducted on mice.
Famous Color-Blind People
And yet color blindness is not perceived as a problem by society, but as a distinctive feature. For example, many artists were color blind, which became the basis of their unique style and color solutions. Experts came to this conclusion when they analyzed the palette of works by Vrubel, Repin, Van Gogh, Savrasov, Merion, and Constable. Can you imagine? A more contemporary example is Viktor Chizhikov, an illustrator for the Murzilka magazine and creator of the world-famous Olympic Bear. He always used a palette with numbers.
And what color is your apple?
Based on open sources.