Human Retinas Grown in a Dish Reveal Origin of Color Vision | Hacker News Reader

Human Retinas Grown in a Dish Reveal Origin of Color Vision

npr.org

119 pointsgumby29 comments

I am color blind. I fail a bunch of dot tests and have had minor social embarrassment over the years talking about colors - I will be in a discussion about color and say something nobody relates to when I misidentify a color.

However, an aside, I am not red-green color blind. I have had several conversations with people who think red-green is the only type of color blindness, or that red-green color blindness and color blindness are the same thing.

Anyway, it sounds weird to me to "cure" color blindess. It causes no problem for me other than minor social embarrassment when talking about colors. I start to fear a world in which it's "corrected" - are the things I have seen all my life "incorrect"? Would I find it weird to see some familiar objects "corrected"?

Based on my conversations with people I would also have to be suspicious that any "cure for color blindness" would focus 100% on red-green and not do someone like me any good.

In the deaf community there is a similar argument against cochlear implants. [1] Personally I'd always welcome enhanced senses and I'm pretty excited about research into interfacing technology with the nervous system.

[1] http://time.com/76154/deaf-culture-cochlear-implants/

>Anyway, it sounds weird to me to "cure" color blindess. It causes no problem for me other than minor social embarrassment when talking about colors.

Sure, but wouldn't we all like to have better senses? We probably don't need more than black and white vision, and a narrow audio bandwidth centered on human voice, in order to functional completely normally in modern society.

Well, I wonder about memories and associations formed around colors. After reading the article I was passing a tree lined street, thinking of what green has meant to me over more than 3 decades. What if it's not "real" green? What if it changed some day?

Also, I don't know, some people seem content with flawed senses. Eg. A lot of people with glasses seem to shrug it off and accept it. It doesn't cause them existential crisis. And that is a much more practically troubling problem than color blindness.

I personally think you should be not affraid, the time to get used to things is mostly not long. See it as an enrichment similar to "I am used to see VHS video and now I am looking at the rich details and colors of Blueray". The experiences stored inside you concerning your lack of vision will in part stay and some of it that is not important for the function of your system later on will be lost.

It doesn't cause them existential crisis, but when Lasik is available for their particular combination of age/condition/money they'll still get it.

> What if it's not "real" green?

It is as real as any approximation to the full spectrum of light can be. But it provides less information about said distribution to you than for trichromats. I can't really understand your feelings, because I will go for near-infrared sensitive cells in my retina when/if the procedure will be feasible and if/when four-color displays and cameras will appear.

> A lot of people with glasses seem to shrug it off and accept it.

Well, I wear glasses to correct shortcomings of my eyes' optical system. I'm not sure I understand why it's shrugging off or why it is so big a problem to wear them.

> A lot of people with glasses seem to shrug it off and accept it.

But for my glasses, I would have gone into the Air Force and been a pilot. So instead I became a nerd :-)

> wouldn't we all like to have better senses

If you watch too many Marvel movies, yes.

I think it is about functionality on a social level.

The genes that are responsible for colour blindness are also responsible for causing tetrachromacy. Colour blindness is seen as a deficiency, requiring a cure, whereas tetrachromacy is seen as an enrichment, yet they are different aspects of the same thing (a mutated cone). "Cure" one and you "cure" the other.

When it comes to genes, where do we draw the line between a difference and a disorder? Disorder is in the eye of the beholder (no pun intended)?

Has functional tetrachromacy actually been confirmed in humans?

If the gene variant breaks the cones, then it's a disorder. If they function fine then it's not a disorder, even if they're different. Why would curing one "cure" the other?

According to a link from a Snopes article, yes.

http://www.digitaljournal.com/article/326976

In a not so rigorous way, others claim they are. For example:

http://nymag.com/scienceofus/2015/02/what-like-see-a-hundred...

Apparently the theory is that a mutation on an X chromosome causes a wonky typically non-functional cone. A male, with one X chromosome gets 2 normal cones and 1 wonky one. A female, with two X chromosome can get 3 normal cones from one X and 2 normal cones and 1 wonky one from the other X, for a total of 4 types of cone. If the wonky one happens to be working they are a tetrachromate. Thus eliminating the gene that causes wonky cones eliminates colour blindness and tetrachromacity.

I wonder to what extent the wonky cone in a colour blind male typically functions? They wouldn't necessarily see fewer colours but different colours. The red-green colour blind people I know can still see the colours as different, just not as distinctly based on their saturation, background colour and whether they are doing a direct comparison. Presumably there is also the remote possibility of a colour blind female being a tetrachromate?

Additional edit: The world is greyer than something simply functioning or not. Assuming a solid definition of "functioning", something can be partially functioning. More generally, one first has to figure out what functioning means.

>However, an aside, I am not red-green color blind. I have had several conversations with people who think red-green is the only type of color blindness, or that red-green color blindess and color blindness are the same thing.

I had a similar discussion here on HN. The main conception of color-blindness was exactly what you describe.

I don't understand why people would make a scene of your mistakes. I'd find it interesting and start asking tons of questions. It is a unique quirk and cool since it isn't really negatively affecting your life

If you haven't already, read The Giver. It sounds like you might enjoy it!

Text-only version:

https://text.npr.org/s.php?sId=656560767

this should be the default when linking from npr

that should be the sane default for most of the web, actually

it is so readable it hurts

this is why I automatically go into reader mode if I don't need to interact with the site

Reminds me to Monet who had a cataract removal surgery and after that he was able to see ultraviolet wavelengths

This should be a scientifically studied endeavor. Imagine when you can go into a Lasik place and get the UV upgrade.

The lens of your eye is what filters out UV light. When the lens is removed because of the cataract, there is nothing to block the UV light, so you can see it.

what is the range of vision without the lens? Is it expanded just on the blue side or do we also start seeing infrared?

It'll probably only expand to the UV side of things, the lens doesn't really filter out IR at all and you can see some of it already without any changes to your eyes. But your eye isn't very sensitive to it, so you have to block out all other light to be able to see anything.

edit: quick way to do this https://www.wikihow.com/Build-Near-Infrared-Goggles

The human lens already lets most infrared through.

https://en.wikipedia.org/wiki/File:Human_crystalline_lens_OD...

Infrared is everything to the right of 700 on the x-axis, and ultraviolet is left of 400. Our lens already lets through about the same proportion of infrared as most of the rest of visible light. Presumably that means that our retina is just insensitive to it.

Would the UV damage your eyes or is a question of intensity?

UV do damage because of energy of a single photon enough to break some bonds. It is the amount of damage that depends on intensity.

Similar to Monet case, one can get a NIR camera by removing the IR filter in front of typical digital camera.

Ambient levels of UV can damage your skin (think sunburns and skin cancer). There is no reason to assume it wouldn't damage your eyes. So wear sunglasses.

Off on a tangent: I always wear sunglasses outside. I don't deal well with light, especially when it's bright. Would love to have that particular vision problem corrected, but eh, probably not in my lifetime.

This was posted yesterday... https://news.ycombinator.com/item?id=18204637

Reply on news.ycombinator.com