[Ricochet]

Go through like paper? Probably not, but let's put it this way; I've had a hard hat literally disintegrate in my hands after a time. If you're talking about safety level eyewear, then the typical rating is one strike or one scratch and they're done. They'll certainly take more punishment, but that's the specs. Ballistic and Paintball grade lenses are supposed to be higher, but after a time, especially if you're cleaning them with chemicals and/or applying whatever anti-fog crap, the lenses will break down, not to mention sunlight, dirt, etc. This may take years however. If your lenses are old, scratched up, or you don't have complete faith in them, then it's likely time for a change. Also look for material breakdown and tiny stress fractures around the edges.