Jana is an amateur everything when it comes to space, nature and science. She loves exploring mysteries, both classic and new.
A Colourful Memory
As a child, my mother would often describe to me the colours of the sea. I saw blue water and white crests, but she talked about turquoise, green lines in between and even pink. These were incredibly difficult moments for me. My mother is one of the most honest people I know. In all my years, I've never heard her tell a tall tale or even lie. Frankly, she hates lies. Thus, for us to stand on the beach, year after year, and this honest woman telling me about shades in the sunset and the water — things that simply weren't there — it made me uncomfortable. I couldn't see what she claimed was there. As it turns out, there are women who see colours the rest of us cannot even begin to dream about. My apologies, Mom.
Meet the Tetrachromats
The condition is called tetrachromacy and thus far, it appears to be an exclusively female one. To better understand how somebody can see colour where there is none (for the rest of us, anyway), you need to look at the eye's biology. The retina is lined with something called cone cells. Nearly everyone has three different kinds of cone cells and each variation registers light on a different bandwidth. When the three bandwidths come together, they blend the colours of an individual's perception. Faulty cones result in colourblindness but tetrachromats have an extra fourth type. Their ability to perceive extra colour is basically supercharged.
The Elite Percentage
Not all tetrachromats have rainbow vision. Let's backtrack, for a moment. To identify somebody as such, a genetic test must be done to confirm the individual positive for extra cones, which technically allows them the title of tetrachromat. However, tests showed that around twelve percent of all women are born with additional cones, but not every one sees the world so vividly. As it were, there is an even rarer percentage among tetrachromats who baffle others with remarkable descriptions of seemingly ordinary shades.
Why Only Women?
Scientists have not discounted the possibility that one day, a male tetrachromat might be found. The reason why guys are so scarce or possibly non-existent in this case could be because of genes. Men only have one X chromosome, women have two. The gene responsible for the eye's sensitivity to green and red is linked to the X chromosome and since women carry a double load, their chances of having a variant of the gene and four cone types are greater. Of course, there's no reason why men cannot inherit this incredible ability, but one is yet to come forward. Considering that the condition is not common knowledge, there may be a few men out there who have no idea that they're tetrachromats.
Colours in the Dark
Seeing in low Light
When researchers studied one woman, who was also an accomplished painter, they noticed something unusual. Her other paintings already showcased the sparkling wonderland of the tetrachromat, but the ones that caught the attention of scientists were those depicting dawn. A genetic test confirmed her as somebody with four distinct cones, and she also claimed to see the colours she transferred to canvass.
The implications were amazing. Usually, dawn limits a human's vision to greyscale. The lady's paintings showed dawn scenes in low lighting, but with plenty of colours. A greater understanding of tetrachromacy is required to confirm the following, but experts suspect the genes responsible for her supervision also enhanced her ability to see when the world darkens for everyone else. Ironically, the same woman's daughter was colourblind.
The Mental Impact
The world may be beautiful to tetrachromats but that doesn't mean the condition has no drawbacks. These women are often not believed when they describe something. They can literally see bright shades where most other people only see monochrome. Since the condition is not widely known, few understand that tetrachromats aren't lying, delusional, or joking. Not being believed can be very discouraging and exceptionally troubling for tetrachromatic children.
Colour overload is another issue. A person with normal vision might walk into a shop and not even notice anything except for the items they want to buy. In the same building, somebody with increased sensitivity might experience a colour onslaught close to hell. Not the deadliest of things, but certainly not comfortable either.
Too Much of a Good Thing
A Lack of Awareness
Tetrachromacy remains a topic you can raise at the dinner table or between friends — or a bunch of strangers on the bus — and chances are nobody would know what it is. The rarity of the condition also makes awareness and by extension, believing the people who see “impossible” shades, so much harder. Despite the drawbacks, few tetrachromats would trade their ability for normalcy. Inherently, they are lucky. The rest of us can only glimpse their rainbow landscape through a tetrachromat's art and verbal descriptions. Let's face it, these look and sound gorgeous. We should be so lucky to see it.
Questions & Answers
Question: Can any companies can do the genetic test for Tetrachromacy?
Answer: Unfortunately, this kind of testing isn't mainstream yet. It would be wonderful if one can just ask your local GP for such a test! At the moment, most people who test themselves for this condition approach private laboratories that cater to the public.
© 2018 Jana Louise Smit