Has anyone developed a type of glass or plastic which converts colored light passing through it into black and white? If not, what would be involved in developing this technology?
I would like to own a pair of sunglasses like this. 
Not exactly what you are looking for, but take a colored filter that passes only a very narrow band of visible wavelengths, preferably green or blue; then darken the filter until it passes so little light that your cones crap out and your rods take over. Not truly black-and-white, but monochromatic in such a way as to make it difficult to determine what the ‘monochrome’ is.
I have no idea, but the question reminded me of some amber parking lot lights I encountered at UC San Diego. They lit the parking lot well, but everything that was bathed in the light appeared to be sepia-toned monochrome. Very surreal.
If you happen to develop these, I would totally buy a pair. I’ve always wondered what it was like to walk around in the 50’s. 
Hmm, I think one of the fundamental problems with this would be that white light is created by a mixture of all the wavelengths of the color spectrum. If you filtered out all the color, there’d be no visible light left. Unless there was some sort of biological loophole?
I think the closest way would be to filter out all wavelengths except a very narrow band. It would look monochrome, but heavily tinted to that wavelength. Another thing, depending on the colored filter you chose, an apple might appear “white” using a red filter, or “black” using a green filter. I put the color in quotes, because it wouldn’t technically be white, but the lightest red the filter would allow… so relatively “white”.
Been watching They Live?
Not only did Roddy’s shades reveal the Evil Subliminal Messages lurking withi n (along with those ball-bearing-eyed Alien Yuppies), I notice that they also turned everything black and white.
Seriously, I can’t think of anything that will do that. If you reduce the light comimng directly through enough to make your vision switch from photopic to scotopic, you;ll still have enough light coming around the sides of the glasses to prevent that. You’d neer goggles that fit all the way around your eyes, and I’m still not sure it’d work.You could wear bandpass filters so that you only saw one wavelength through the glass, but that wouldn’t really be “black and white” – it’d be “green and white” (or “red and white”, or whatever pass band you’d selected).
You can buy monochrome viewing glasses - I have one in my camera bag - they’re designed to remove the distraction of colour so that you can appreciate contrast, pattern, texture, etc - and are specifically designed for photographers shooting in B/W.
What you see is monochrome, but as others have said, is heavily tinted, because all the filter really is, is a piece of glass tinted to pass only a narrow range of wavelengths. It makes everything look different intensities of a sort of orange-sepia colour.
A filter method for this must be impossible.
Imagine you’re looking at something that’s a pure, intense green. In black and white, it should appear a reasonably light grey. But to do that your eye needs to see some red and blue, because grey is a mix of the primary colours. A filter can’t add light.
The only option is something that detects all frequencies of visible light and emits its own light. Obviously this is the case with, say, a camcorder. But I don’t know of any simple device that performs only the function of greyscaling.
On edit: I’ve realised that far from impossible, there’s a simple way to do this. Use a filter that blocks out a lot of light (very dark sunglasses). If the light that gets through is dim enough, you’ll perceive only black and white even though in reality the light coming through the filter is still coloured.
A lens and CCD imaging chip driving a display screen accomplishes this.
There are also image intensifiers of various sorts that do this, like night vision goggles.
Also, there are various phosphors that will fluoresce when illuminated by light of short enough wavelength. Some of them fluoresce in the IR when they are illuminated by visible wavelengths.
None of these fit the bill entirely, but they all do some kind of conversion to turn a multitude of wavelengths into a single one.
I think if you used the “monochrome” glasses mangetout described, you would lose the sense of color after a few minutes, and it would feel very much like what you’re after. That’s about as close as you can get to monochrome with just a lens.
I assume the photographer’s monochrome glasses are meant to simulate what’s called “panchromatic” film. You might get a stronger monochrome effect with a pure green filter, which would simulate old orthochromatic film or a B&W TV monitor (which usually just displays the green channel).
You can probably try this pretty cheaply. Get some cheap plastic safety glasses and green RIT dye. Soak the glasses in a hot batch of dye and they should turn green. The longer they soak, the greener they’ll get. I’ve done this to make colored filters for submini cameras. While you’re at it, get some red dye and make yourself a pair of rose colored glasses.
YMMV. Different plastics might be more or less susceptible to the dye.
IIRC, two pairs of 3D glasses (the kind with one red and one blue lens) held up to each other gives black and not black. It’s not exactly white, but it basically plays on the double filter idea the above posters are referencing.
Yes - our visual system has a ‘white balance’ function (which is why we are able to see white paper as white under various different artificial light sources) - I think after a while, the world would start to appear black and white, rather than black and orange.
Yes - that’s what mine is, I’m sure (although it’s years since I used it). I think other types are available.
Thanks for all of your responses, fascinating stuff!
As a work around for “true” black and white, you could probably fashion something akin to a (really small) camcorder in each of the lenses that runs through a chip to perform the relatively simple process of auto-grayscaling all images (I’d assume it’s simple, it has to be a basic set of algorithms that makes 255,152,123 = x,y,z in grayscale) . I’m not sure how cost prohibitive (or plain klunky to wear) these would be though.
Enough water filters out all color, but that doesn’t seem to be practical. 
Really? I haven’t heard this.
Certainly you can see through tens of metres of clean water and still perceive colour.
Are you saying that it acts as a blue filter over enough distance?
I doubt it. It’s true that our visual system is aware of ambient light and “corrects” for it (we can be aware of an object’s “true” colour despite ambient light). But we’re still aware of the ambient light and therefore I don’t think it’s true that looking through monochrome glasses is the same as seeing black and white.
The other objection of course is that a normal, subtractive, filter doesn’t preserve as much information as a greyscale pass. Some things would appear dark simply because they are among the colours that are being filtered out. So even if it did seem like greyscale, it would only be superficially so.
Just about any of these should provide a monochrome experience. I agree with above that, after a period of immersion in a monochrome environment, the base “color” is less than noticable.
I think the colour tint would become less noticeable after a while - if the goggles completely enclose the eyes so that no light spills in from the sides, there would be no reference point and the visual system would be forced to adapt to the information it has got. Even without completely enclosing the eye, this happens - If I wear rose-tinted spectacles (yes, I really do have a pair, somewhere), it doesn’t take very long for the rose tint to be unnoticeable - and the whole world seems bluish when I take them off.
That’s completely true, however, if the desired effect is that approximating a B/W vintage movie, it might still be good enough, as some B/W film stock has similarly narrow sensitivity.
This calls for some experimentation, I think…
Yep, good point, that’s pretty much my experience too. I take back my first point.