[LoganDark]

There are glasses that, AFAIK, shift the wavelength of incoming light in some certain way such that a colorblind wearer can differentiate real-world colors that they'd normally have trouble telling apart.

It doesn't magically allow colors to show up that they're physically incapable of perceiving, but AIUI it shifts real-world colors that they'd have difficulty telling apart into other colors that they can tell apart, if that makes any sense.

[eru]

I'm not sure about shifting wavelengths (that seems way too complicated), but you could just block all out the red light on the right eye and all the green light on the left eye, and that would do the trick for someone who's red/green blind.

[LoganDark]

Maybe, though that assumes they have two fully functioning eyes. I'm not colorblind, but my two eyes can't work together because they don't converge. I wouldn't be able to rely on building a complete image from two incomplete signals; I need a complete image in my left eye in order to see.

[eru]

Yes, you'd need something different.

Instead of putting these two filters on different eyes, you could put them one after another in time, I guess.

Or you could put a green-blocking filter on the left side of your view (on both eyes) and a red-blocking filter on the right side of your view (on both eyes), and you would move your head around a bit to figure out green from red.

Or you could have a checker-port pattern with the two filters or so.