go to whitearmor.net (First Imperial Stormtrooper Detachment) and go to the forums, sales area and look up smitty's thread. He makes killer lenses (flat, concave, bubble) out of shade 4 welders goggles (You can see out, they can't see in, not even with a flash)
I'd link, but you need to be registered and logged in to the forum (you can use your MEPD info to reigster quickly like you can on all 501st boards, just go to register first) before you can see sales area.