My thoughts as well. If you're lacking the color receptor, there's no way you're going to "see" that color in the conventional sense. But with the glasses, you can at least discern it's there by up or down shifting the frequency.

We don't have "color" receptors, we have "wavelength" receptors. Your red and mine may be different perceptually while we still can say we see "red" and are not blind to "red." If there are a dozen nanometers difference in our receptors, we wont see it the same, but we'll see it.

Philosophiziationarianism! That'll be ten cents, please.

OK, I just went to the site. Seems they are notching out specific bands of light to purify the resulting light striking the receptors. Very clever. Do have a look.

http://www.enchroma.com/technology/how-it-works/

In the human population there's a few different cones that have different center frequencies roughly in the red or the green, and so in most cases of colorblindness there are people who have gotten two different reds or two different greens. This is also why colorblindness is way more common in males than in females, because the genes that encode the color receptors are stored on the X chromosome. (This is also why tetrachromatism is a thing in females, with probably the same incidence rate as colorblindness in males, but it's one of those things that's hard to perform a study on since people tend not to realize that their color perception is abnormal so it's easier to find people who lack something rather than having something extra.)

These colorblindness glasses probably work by amplifying the difference between the two reds or the two greens, probably with a notch filter or carefully-controlled destructive interference or the the like. They still aren't seeing the full spectrum but it does help them to differentiate between the different frequencies much better.

I know that back in the 90s there were glasses that helped to differentiate red and green for the purpose of driving more safely. I have no idea what principle they worked on though - this was just according to a colorblind friend of mine who said he'd used them but that he didn't really need them since he used the lights' positions instead.

I'd be interested to see what the world looks like through these glasses as someone with normal color vision, especially looking at monochromatic color sources. It'd also be really interesting to know how a tetrachromat sees the world through them (although getting an actual description that makes sense goes deep into the realm of qualia).

The difference between what you describe in the 90's and this is the degree of precision one can lay out the diffraction lens patterns. Apparently with a large number of strategically choosen narrow notches you can get a bigger effect than with just a single broad notch.

I'd imagine looking though the glasses might be like increasing the saturation on an old color CRT monitor. The primary colors becoming more intense at the expense of the more subtle hues and shading.

cool

cool

damnit.

For you.