Colorblind cure comming in 5 years? Also tetrachromat vision possible?

Question

I read articles about a cure for colorblindness and giving trichromats tetrachromatic vision! It involves injecting harmless viruses with gene code for different color pigment cones. They will then grow on your retina and youll be able to see a wider range of colors! Dichromats see only 3 or 4 colors on a rainbow(brown, yellow, blue, sometimes gray) Trichromats see 6 or 7 colors(red, orange, yellow, green, blue, violet/purple) while tetrachromats may see 9, 10 or even more colors!(crimson, red, magenta, bronze, orange, yellow, lime, emerald, green, teal, blue, cyan, purple and often they see colors that aren't even named and can only be aproximated to a similar named color) I heard that there is almost as big a difference from 3 to 4 cones as there is from 2 to 3. Who here is colorblind and wants a cure? Who here wants to be tetrachromatic? I do! I love colors!

one source:

http://www.ryansutherland.com/media/tetrachromats.pdf

Answer 1

There are unconfirmed reports of tetrachromatic vision in humans. It is frequently found in other animals, birds especially. There is little survival advantage, in humans, for such precise vision, which is why most of us are trichromic.

Your description of seeing colors is a little over simplified. Most humans with normal vision can see in excess of 1 million shades as each cone can distinguish over 100 shades of RGB (100^3 = 10^6). Tetra could potentially see 10^8 shades.

I would hold off on claiming this is true until more concrete testing is done (genotyping and phenotyping), but not many volunteers are going to allow their eye to be removed for the phenotyping.

As for genetically engineering humans to see 4 shades...why? Ok, I agree going from 2 to 3 would help some people, but 3 to 4 is virutally useless.

In addition, inserting genes is more than 5 years away. We have done a remarkably poor job of inserting genes into humans and in recent memory (1999) a U of Penn researcher killed a 18 or 19 yo man with gene therapy.

We have cured cancer and fixed innumerable genetic defects in mice, but humans are a tad more complex. Most of these gene therapies indescriminately drop their genes into the DNA. Often this disrupts an existing gene and in the worst cases can cause new diseases or spark a cancer. Is tri or quad color vision worth this risk right now?

Some of the tetrachromatic vision articles:
http://scienceblogs.com/cognitivedaily/2006/07/do_women_perceive_color_differ_1.php
http://www.post-gazette.com/pg/06256/721190-114.stm

Answer 2

I am afraid that while you've read this in the papers, it will take longer than that to actually get this therapy in the market.

Also people who are colourblind, are so due to genetic reasons and hence it would require change at the genetic level, now since cells in the eye don't regenerate, this would be quite impossible until and unless they are grafted with corrected tissue using a combination of techniques involving stem cells and viruses.

About tetrachromatic vision, it's quite difficult to extrapolate results of experiments done on mice to humans since addition of a new gene for another cone pigment would also entail re-wiring of the visual centres of the brain and thus could form corss-wiring and lead to unexplicable problems.

So even though the future seems bright, we need to trudge carfeully.

Answer 3

1

Answer 4

You have a refined sense of humor.