Do you see colors better than others? Let's talk about Tetrachromacy!

Have you ever wondered if you could see more colors than the seven colors of the rainbow? Or have you ever argued with a friend about the color of a dress, saying, "No, no, this is this color," or "Oh, no, this is that color?" If so, you may have a very rare, special, superpower. Today we're talking about the ability to see colors in such an unusual way. We call this tetrachromacy.

What is Tetrachromacy?

Simply put, tetrachromacy is a rare, extremely sensitive color vision condition that only occurs in some women. It's not a disease, it's a trait.

Inside our eyes, there is a part called the retina. It contains special types of cells that detect light. We call these photoreceptors. There are two types of these cells. One is the cones, and the other is the rods. Rods help us see in black and white and in low light. Cones are mainly responsible for seeing color.

Normally, we all have three types of cone cells in our eyes. Using these three, we can distinguish and recognize about a million colors.

However, people with tetrachromacy have four types of cone cells in their eyes. Because of that fourth cone cell, they can see hundreds of millions of colors, which is about a hundred times more than a normal person. Imagine, they can see thousands of different colors just for the color red we see.

How does this fourth cone cell work?

First, let's look at the three types of cone cells that we all normally have.

• Red-sensitive (L-cones): These are called 'L' (Long) cones because red has a longer wavelength.
• Green-sensitive (M-cones): These are called 'M' (Medium) cones because they are in the middle of the visual spectrum.
• Sensitive to blue (S-cones): These are called 'S' (Short) cones because blue has a short wavelength.

A person with tetrachromacy has a fourth type of cone cell in addition to these three types. This is usually more sensitive to the range between red and green, or orange. This extra cone cell is caused by a genetic mutation .

Now you might be wondering, how can you see so many colors with just one extra cone cell? Imagine you are painting. You have three primary colors (red, blue, green). You can make many colors by mixing them together. Now if you had a fourth primary color (yellow, for example), how many new colors would you be able to make? That's what happens in the brain. The information from the extra cone cell is combined with the information from the other cone cells, and the brain creates a very detailed world of colors.

Why does this often only happen to women?

This is the most interesting part of this. The reason for this has to do with our chromosomes.

The gene that controls the cone cells that help us see red and green is located on the X chromosome .

As you know, a male has one X chromosome and one Y chromosome (XY). So, if that gene on that one X chromosome is mutated, all of his red/green cone cells will be changed. That's why men are more likely to have color blindness.

However, women have two X chromosomes (XX). So, one X chromosome can have the normal gene and the other X chromosome can have the mutated gene. In that case, the woman's eyes can produce both normal cone cells and extra cone cells caused by the mutated gene. About 12% of women have this gene.

1. The fourth cone cell must be sensitive to a different frequency: If the new cone cell is sensitive to the same colors as the other cone cells, the brain will not receive any additional information. So no difference will occur.

2. The brain needs four color channels: The human brain is normally designed to process information using three color channels. So even if there is a fourth cone cell, if the brain does not have a fourth channel to receive that information, it cannot take advantage of that extra ability.

Therefore, people with this super color vision are very, very rare.

So, can't you take an online test to see if you have this ability?

If you search the internet for "Do you have tetrachromacy?" you'll find a lot of tests. But none of them are real .

The reason for this is simple. The screen on your phone, tablet, or computer is made up of only three color channels: Red, Green, and Blue (RGB) pixels. So, it's impossible to test your eyes with four color channels on a screen that only uses three color channels.

True tetrachromacy tests are performed by scientists in laboratories, using high-tech, expensive equipment , DNA testing, and controlled light environments.

How does someone with tetrachromacy see the world?

This is something that is difficult for us to understand exactly. Because colors are a very subjective experience. What you see as red is not the same color that I see. There is a slight difference.

But if you look at it numerically, here's the difference.

When you look at this chart, you can see the difference, right? It's a truly amazing ability. These people can experience hundreds of thousands of times more colors in a flower, a painting, or a sunset than an average person can.

So if you suspect that you have this ability, even though it is difficult to prove it, be happy that the world you see is colorful. It is truly a special gift from nature. If you feel any difficulty or change in your color vision, it is best to talk to your doctor, especially an eye surgeon, about it.

Tetrachromacy, color vision, how to see colors, cone cells, genetic mutations, eye health, tetrachromacy Sinhala, color vision