Jana is an 'amateur everything' when it comes to space, nature and science. She loves exploring mysteries, both classic and new.
Tetrachromacy: A Colourful Memory
As a child, my mother would often describe to me the colours of the sea. While I saw blue water and white crests, she mentioned turquoise, green lines and even pink.
This was confusing and difficult for me. My mother is the most truthful person I know. For us to stand on the beach, year after year, and having this honest woman describe 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. 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. Huh? Let's backtrack, for a moment.
To identify somebody as such, a genetic test must be done to confirm that the individual has extra cones, which technically allows them the title of tetrachromat. However, tests have shown that around twelve per cent of all women are born with additional cones but not everyone sees the world so vividly. As it were, there is an even rarer percentage among tetrachromats and these are the people 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 could be related to genes. Men have one X chromosome and 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.
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.
Seeing in Low Light
When researchers studied one woman, who was also an accomplished painter, they noticed something unusual. Her other paintings showcased the sparkling wonderland of tetrachromats. But the ones that caught the attention of the scientists were those that depicted dawn. A genetic test confirmed her as somebody with four distinct cones, and she also claimed to see the colours that 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 the world clearly when it darkens for everyone else.
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.
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 you are talking about. 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 the lucky ones. The rest of us can only glimpse their rainbow landscape through a tetrachromat's art and verbal descriptions.
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
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