I bought the Laserwave RGB glasses that Stanwax sells some time ago for around £40.

Whilst some people have criticised them since, and I certainly haven't run any scientific tests to ascertain the amount of light passed, what I can say is that with my laser there are significant reductions in the amount of visible light. Whether or not the levels are safe, I really couldn't say but they do seem to reduce very bright beams down to quite dim beams which at least gives me some confidence of a decent reduction in exposure should I suffer a hit.