Sunglasses that could correct colour blindness

[LONDONER]

Colour blindness is more common that you think and its correction can lead to unexpected results:

http://www.smithsonianmag.com/innovation...56/?no-ist

[Insertnamehere]

Hmm as I understand it, rhodopsin mutation amounts for a lack of fiktering capability bewteen red and green wavelengths which are dangerously close in value.

Usually equipments like spectrophotometers have slits and wavelenght filters to select a particular wavelenght from a full light source, so are these glasses supposed to act as these?

It wasn't very clear in the article, but if that's the case, that sounds pretty neat.

[matty7]

they actually look good too instead of them screaming look at me im colour blind - I could do with a pair just to read our rainbow coloured names that we get for a 1000 posts, some letters are virtually not there for me

[meridannight]

people who actually lack either the green or the red cone are not able to distinguish between them wearing any kind of glasses you give them. they are physically incapable of detecting three different spectral components in the electromagnetic wave of light, necessary to see the three components of red, green, and blue. they can only distinguish two. and thus they are incapable of seeing reds as different from greens, for example. there is no way to correct it. a person would need an actual third cone type on their retina, peaking at a different wavelength from the two he has, to be able to make that kind of discrimination.

this is the same as claiming you can make magneta by continuing mixing green and red, just a bit intenser green or red. it is full nonsense.

what is actually going on, and what they don't tell you about, is that some people have a deficient trichromatic color vision, rather than actual color blindness (non-existence of one cone cell type). people who have a deficient color vision like that have three cone cells, but one doesn't function as well as the others and as well as it does in normal individuals. it's called anomalous trichromacy. in essence, the spectral sensitivity of the affected cone is a bit off. but the cone cell is not missing, like in dichromacy.

nothing can cure actual color blindness. if you don't have the third cone, the third spectral component does not exist for you. it's impossible to correct that without physically manipulating your retina and the nervous system, which, also, is impossible.

this is a bogus campaign, because they present their product as some sore of 'cure', when, in fact, it only helps those individuals who are not actually color blind at all. and even then, it won't help them all the way, or 'restore' normal color vision for them. it just improves spectral discrimination to a degree. to how large a degree depends a lot on the degree of cone malfunction in that particular individual. ergo, this thing is complete bogus.

most color-blind individuals are anomalous trichromats rather than complete dichromats. In practice, this means that they often retain a limited discrimination along the red–green axis of color space, although their ability to separate colors in this dimension is severely reduced.

and:

Lenses that filter certain wavelengths of light can allow people suffering from a cone anomaly, but not dichromacy, to see a better spectrum of colors, especially those with classic "red/green" color blindness. They work by notching out wavelengths that strongly stimulate both red and green cones in a deuter- or protanomalous person, improving the distinction between the two cones' signals.

[Insertnamehere]

what is actually going on, and what they don't tell you about, is that some people have a deficient trichromatic color vision, rather than actual color blindness (non-existence of one cone cell type). people who have a deficient color vision like that have three cone cells, but one doesn't function as well as the others and as well as it does in normal individuals. it's called anomalous trichromacy. in essence, the spectral sensitivity of the affected cone is a bit off. but the cone cell is not missing, like in dichromacy

Ok, thanks for this.

This is, then, what I read when I looked at rhodopsin mutations. Certainly a mutated protein is different than an entire comprimised cellular type.

The problem, then, seems to be in the close value for red and green wavelenghts which are not resolved unless you have a specific cell type with a specific photosensible protein that responds to it.

If so, you are correct. If the entire photoreceptor isn't there, it doesn't really matter what you do with the light inciding in the retina.

[Camfer]

nothing can cure actual color blindness. if you don't have the third cone, the third spectral component does not exist for you. it's impossible to correct that without physically manipulating your retina and the nervous system, which, also, is impossible.

Gene therapy has already "cured" red green colorblindness in monkeys. I expect to see it widely available for humans within my lifetime.

Here's a monkey that was trained to get a reward (a squirt of grape juice) when he could ID a colored shape in a field of dots. Before gene therapy he could not find reddish shapes. After treatment, he could.




Read about it:
http://www.neitzvision.com/content/genetherapy.html

http://www.npr.org/sections/health-shots...ss-therapy

[meridannight]

Gene therapy has already "cured" red green colorblindness in monkeys. I expect to see it widely available for humans within my lifetime.

Here's a monkey that was trained to get a reward (a squirt of grape juice) when he could ID a colored shape in a field of dots. Before gene therapy he could not find reddish shapes. After treatment, he could.

okay, i forgot about gene therapy. but i did say this:

it's impossible to correct that without physically manipulating your retina and the nervous system, which, also, is impossible.

i just forgot that gene therapy might be able to do something like that.

unfortunately they don't specify whether the monkeys that benefited were dichromats or anomalous trichromats. dichromacy is a 2-bit-depth visual processing, whereas anomalous trichromacy is a 3-bit processing. in order for the dichromat to see three distinct colors their brain needs to learn to represent and interpret the visual signal in increased bit depth. it would be interesting to know if that was even possible, but the articles don't treat this crucial information at all.

[meridannight]

This is, then, what I read when I looked at rhodopsin mutations. Certainly a mutated protein is different than an entire comprimised cellular type.

The problem, then, seems to be in the close value for red and green wavelenghts which are not resolved unless you have a specific cell type with a specific photosensible protein that responds to it.

yup.

by the way, did you know that birds have a 4th cone cell type? or tetrachromacy, as it is. (and some insects and butterflies have been found to have 5 cones even). that makes 4 distinct primary colors for their vision. red, green, blue, plus the fourth. and everything is a combination of the simultaneous activation of these 4 cones. they can also see into the ultraviolet spectrum as a result.

[Camfer]

unfortunately they don't specify whether the monkeys that benefited were dichromats or anomalous trichromats.

Squirrel Monkeys, like all new world monkeys, are dichromats. So they took a dichromat and turned it into a trichromat.

Human trials within 2 years at the University of Washington.

I'm usually classified as a dichromat, so this could be really big for me someday.

[Camfer]

Bees don't see red but do see UV. Many flowers have UV patterns that human eyes do not see. Do a search on UV pictures of flowers to see it. So in a sense, all humans are colorblind.