Lasers
Ok, so how long until they get rid of the glasses and do this with contact lenses? (Ohoh, did I just ruin someone's patent application?) ;-)
Umm, when are they going to mount them on sharks? (You knew that someone was going to ask that question, didn't y'all?)
As for the screen burn-in problems, that's mostly to do with sputtering of the electrodes by the electron/ion current in a plasma display (And, there was a similar burn-in problem for certain monochrome CRTs, caused by the electron beam, for a static image, burning the phosphor coating.). That shouldn't be a problem for lasers, at least as long as they don't go with an ultraviolet laser, which could cause some burn issues (Ohoh, did I just ruin someone else's patent application?).
Or, use a ultraviolet laser, and paint a phosphorescent strip on your arm, allowing the laser to make the phosphorescent area glow/fluoresce, seemingly by magic. Perhaps image this with a optically filtered camera (on the other side of the glasses?) to perform the detection. (Ohoh, another idea publicly disclosed?).
Oh, yeah, don't forget that most laundry detergents include a "whitening"/"brightening" agent, left behind after the wash cycle is complete, which is actually a fluorescent material.
Dave
P.S. I'll get my coat. It's the one with the optical brightening agent on it.