What if you and I see different colors? Like when I see red, it’s the same as when you see blue and vice versa? A classic Deep Thoughts thought experiment that isn’t actually that deep, because everyone thought of it when they were like 15. If we each saw different colors, there would be no way to know. End of thought experiment.
But here’s a deep thought. The fact that we see different colors is just a true fact about the world, and we have a way of knowing that it’s true. Because when I see red and green, they’re on opposite ends of the color sensory spectrum, while for other people the difference between red and green is much more subtle. We do have ways to compare private experiences! Take that, Wittgenstein!
Anyway, colorblind glasses. This is a product that supposedly helps colorblind people see color. I learned about them from a video by Anne Reardon. Reports on effectiveness seem pretty mixed, with some saying the it makes the colors look more vibrant, some saying it helps them perform better in color tests, and some saying it doesn’t make much difference at all.
Supposedly the glasses work by filtering particular wavelengths of light. Kind of like laser safety glasses, except that I can actually find detailed specs sheets showing how laser safety glasses work, while the colorblind glasses are kept a mysterious secret. I suppose there are some wavelengths of light that are about equally visible to red and green cones in the eye, and these wavelengths don’t really help you distinguish color, they’re just noise. So maybe by blocking them out, these glasses help some colorblind people see colors better?
The problem with the colorblind glasses is they’re trying to offer a sensory experience, or at least that’s part of the sales pitch. People with full color vision have an emotional attachment to the sensory experience of distinguishing red and green, and they want their colorblind friends to share in that experience. As an ace I find that problematic. What if instead we abandoned all pretense of creating a sensory experience of color, and focused exclusively on the functionality of distinguishing red and green?
The thing is, you don’t need fancy laser safety glasses to mechanically distinguish color. You could use much more ancient technology, like stained glass. What if we had glasses that are red in one eye, green in the other? You could distinguish the colors based on which eye could see them. Or another way to do it is to have a subtly textured green filter, so that you could use the texture to identify red.
I’m sure there’s some problem with this solution, or else we would already be doing it. Maybe they’d be pretty annoying to wear. Or maybe the functionality of colored vision just isn’t important enough.
The functionality of coloured vision used to be pretty important to people working in electronics, in the olden days when you needed to be able to read off the coloured bands on resistor to know how many ohms it was.
Of course, it’s 2025, so for starters hardly anyone nowadays is plugging resistors into a breadboard or soldering them onto a PCB by hand, so that application has kind of gone away. But I don’t think it’ll have been replaced by anything similar in any other field because nowadays we’re generally more considerate of people with developmental differences, to the point of there being standards and in some cases actual laws making it a requirement not to discriminate against people who are e.g. colour blind.
tl,dr; we can’t have the world like we used to any more because of woke.
A little while back I watched three videos on this category of product. The first was positive. The reviewer said that it enabled him to distinguish blue and purple, and made reds, pinks and oranges more vibrant. I was sceptical so I looked for further opinions. The second was from SciShow, which was surprisingly sanguine (and explained how they work). The third said that they are a scam.
They are not a single product. My takeaway was that at the less reputable end they’re a definite scam – cheap rose-tinted glasses sold at a high markup, and at the more reputable end the benefits are oversold.
They address the commonest causes of colour blindness (protanomaly and deuteranomaly). In these both red and green cones are present, but mutant rhodopsins cause the frequency responses of the two types of cones to overlap more than usual, so red and green are less distinguishable.
Colours can be distinguished by brightness or by hue. Cutting out some frequencies allows people to pass colour vision tests that they would otherwise fail, by introducing a brightness contrast in a test plate which under normal conditions only has a hue contrast. So with these glasses someone could can pass a colour vision test, but still be unable to distinguish red and green lights.
The more reputable products have a narrow yellow band filter, which cuts out light which stimulates both red and green cones. This makes green and red objects more distinguishable, at the expense of reducing your ability to see yellow. If an object is yellow because it reflects red and green light it still looks yellow (both types of cones are stimulated), but if is yellow because it reflects yellow light it looks much duller (stimulation of both types of cone much reduced), and, perhaps, depending on the full spectrum, could look just about any colour.
If you lack one type of cone, cutting out yellow light isn’t really going to help. Cutting out green or red light wouldn’t much help either. Cutting out green light would allow a distinction between bright green and bright red, at the cost of losing the distinction between bright green and dark red.
With regards to your suggestion of a textured filter, a potential problem is that the eyes don’t look in a fixed direction. The flicker around (saccades) so more parts of the scene are sampled by the fovea (the bit of the retina which provides high resolution imaging). I find it plausible that the effect of this process would to be average out the texturing.
I’m pretty bad with colors. red/green, blue/purple, brown/green, pink/grey.
Aside from that, I’ve always had good visual acuity, and decent low-light vision.
Last time I read up on it, I didn’t really fit any of the standard ‘types’ of colorblind, so I’m just a weird outlier.
I don’t think it causes me much problems in day to day life. For battery charge indicators that use red/green LEDs, I just keep a pair of red and green plastic bits near by, and see which one the light will show through.
have had trouble with electronic/wiring using written directions, but have managed to work around that the few times I’ve needed to.
Have trouble with red/yellow traffic lights – green just looks white to me. I can usually tell by position, but if it’s a single flashing light at an intersection, I assume it’s red, stop, get honked at, and well, that person can just wait five seconds.
I guess I can’t do night-time plane/boat stuff, oh well…
This is a good point- “People with full color vision have an emotional attachment to the sensory experience of distinguishing red and green” – people often make it about “it’s so SAD that they can’t see the full range of color and therefore are missing out on The Beauty Of The World” rather than what would actually be practical and helpful for colorblind people.
Hats off to UK traffic light designers who took colour difficulties into the design stage decades ago.*
For example: if you struggle with the difference between red and amber, then when either is illuminated, you stop. And the red one is the one at the top if you’re close enough to need to know the difference. If two are illuminated, then you were already stopped, and green is next.
* (Caveat: There is a fascinating video on youTube which goes into some awkward early designs around pedestrian crossings, long since abandoned.)
Thankyou @AnotherStewart, that was a genuinely useful comment. I wish I had that information a few years ago when I was trying to help my father in law with his colour vision (which he resolutely refused to have assessed or even categorised).
These glasses may help with specific tasks, by making it easier to disinguish a particular pair of colours. The trade-off is that they will make it more dificult to distinguish a different pair of colours. Unfortunately one of the most common tasks they are likely to be used for is attempting to pass a colour vision test. This is why colour vision tests are supposed to be administered under standard conditions (appropriate lighting, no coloured lenses, etc), and roles that have a colour vision safety standard usually use a range of different tests.
The video covered it pretty well, as well as giving me no reason to alter my assessment of Logan Paul.
Using glasses with different tints in each lens introduces a new set of problems, apart from looking weird. Humans have a limited tolerance for differences between the images in each eye, which varies between individuals. While some difference in the images is essential for one aspect of depth perception (stereopsis), too much of a difference can mess up depth perception and cause discomfort, double vision, or suppression of the vision in one eye.