Recently been in the market for a green laser I think I know where these new more powerful green lasers are coming from. I doubt it would be wise to post a link, but it isn't eBay.
They're what may well be a Class 3b, it comes with no sort of warnings or instructions and to be honest is far to powerful for use in your average lecturing situation (Night time range of a mile or so and a bright sunlight range of maybe 100 meters is just OTT).
In terms of eye protection, not really a chance. Testing mine on a few pairs of sunglasses it just goes straight through with no visible attenuation.
Quite frankly I was surprised that they were a) on sale b) easy to get hold of and c) so cheap. I'm sticking to an old class 2 red.