MADRID, 2 March (EDITIONS) –
Do all people see the same? The obvious answer is no. Everything depends on many factors and for this and for several phenomena that are related to our vision, we interviewed the neuroscientist Conchi Lillo, biologist and doctor in Neuroscience, as well as a professor of Biology at the University of Salamanca, and a researcher in the area of neurobiology of vision at the Institute of Neurosciences of Castilla y León.
He has precisely published ‘Open your eyes! (Next Door Publishers), a book in which he deals with numerous ins and outs of our vision and explains everything from how we see to why we all see (or not) differently or the same. One of the things that has caught our attention the most is that there are people with super vision; Yes, they are able to see more than others, specifically more colors than others, and it is also notable that these are mainly women.
He says that this is not usually the case in men and, although he recognizes that it is an issue that “is not sufficiently investigated”, he recognizes that it is related to color blindness: “It has been seen that women who pass color blindness to their offspring, they “They themselves have the possibility of having a vision richer in ranges of colors. Color blindness is the result of mutations in genes that encode the proteins that respond to the color red and green.”
But we go in parts. It states that humans are trichromats, that is, we have three different types of cones (photoreceptors, specialized sensory cells in the retina of the eye; one red, one green, and one blue), but in people with two X chromosomes, Most of them are women, it has been seen that mutations in one of the copies of the genes to distinguish green or red on one of the X chromosomes produce another type of cone, and they become ‘tetrachromats’, since they will have the three types of normal cones, plus the one that expresses the mutated protein.
Consequently, they can distinguish many more shades than those of us who only have three cones, says the director of the Electron Microscopy service at USAL, and member of the Board of Directors of the Spanish Society of Neurosciences.
“It is not very common, but these women instead of distinguishing a million color range, what trichromats (three types of cones) see, tetrachromats perceive up to 100 million different colors. It is something that can be called super vision, although it does not go beyond the visible spectrum of what we normally see, but within it you can see more nuances between the different colors,” clarifies Conchi Lillo.
The answer is no and this not only depends on the brain, this neuroscientist clarifies: “We do not see the world as it is, but as we are. Our eyes are like the window to the world, receiving visual information, but with what we interpret it. It is with the brain. With that window to the world, the retina, which is what receives the information, until it reaches the brain and interprets it, there are many different steps that make each of us have a particular vision of the world; not so much physiological level, which is very similar in all, except in cases of color blindness or serious visual problems, but when observing an image we interpret many of our own experiences.
Thus, he states that there are people who can be more or less surprised by works of art, and in the end this is because when we see something we really fill in what we are seeing with our personal and emotional experiences. “Although physiologically and physically we see the same thing, what we interpret from what we see has a lot to do with our brain,” insists the researcher at the Institute of Neurosciences of Castilla y León.
Here it stands out, for example, that the Eskimos can distinguish up to 40 types of white, while the same thing happens to the inhabitants of the jungle with green. Do they have different abilities than ours? He insists that in these types of situations, the social and educational part, and the person’s environment, come into play a lot, because in the end what we see is not only determined by our visual capacity, but also by training. “If you are surrounded by different shades of green, for example, you eventually learn through habit and exposure to distinguish more shades than other people,” Lillo emphasizes.
In fact, he maintains that this would also happen to people who are dedicated to fashion, decoration, or graphic designers or painters, who are constantly very exposed to different colors. “In the end they learn to distinguish so many shades, while for other people the colors are very similar to each other. Of course, I don’t know if they distinguish them better because genetically they are also predisposed to also be able to differentiate those colors, or because they are continually exposed to the different tones. In the end it’s a bit of both,” he remarks.
On the other hand, we question this expert about the blue eye color that, as she claims, does not exist, and whose explanation is based on the fact that human beings and many vertebrates do not have blue pigment, we do not generate it, so the one we see in the eyes is due to a similar optical effect and through which we see the blue sky.
“We only have two types of pigments, melanin, in our body: one dark brown and another like reddish orange. The mixture of the two causes us to have different colors in our eyes. In the case of blue eyes, we see them that way because Those eyes have very little melanin of the two types that we have mentioned, and this means that when any type of light enters the eyes, in the same way that light is dispersed in the atmosphere, and that is why we see the blue sky, so It does it in the eye, where it also disperses because it cannot be absorbed by melanin,” says Conchi Lillo.
Finally, we are all clear that it is around one year when the color of children’s eyes is defined and remains more or less what they will be like in adulthood, but for a large part of the population it is unknown that the color of the eyes changes over the years: “From the moment you are born, the color of your eyes changes, and even specks appear in your eyes that you did not have, some areas are lighter or darker, or the amount of melanin inside can change. of an eye due to the amount of light that is illuminating your eye at a given moment; and the consolidation of the pigmentation of your skin, your hair, and your eyes changes over the years.
Although we may not realize it, it also states that the eye is irrigated by blood vessels, and if there is a problem, such as diabetic retinopathy, there may also be some small change in the pigmentation of the iris over the years.
“The color of our eyes and our skin depends on the sum of many factors and one of them is the amount of melanin we have. This comes from the expression of 400 different genes. So the color of your skin, your eyes, and your hair is determined by the number of those 400 genes that have been expressed,” he adds.
Furthermore, the biologist and doctor in Neuroscience points out here that children are born with poor pigmentation and little by little it is consolidated and that is why it is essential to protect them from ultraviolet radiation on the skin and eyes, because they do not have consolidated pigmentation. pigmentation: “You should also wear sunglasses to protect yourself from the sun’s ultraviolet radiation. We are aware of the importance of protective cream on the skin, especially in children, but we forget about the eyes.”
