I used 1500 grit wet sandpaper & then polishing compound. They came out crystal clear.

I saw absolutely no "film" on the front of the lenses when doing this. Just plain plastic (polycarbonate/lexan/etc) lenses.
Some of my rock hits were too deep to get out and they still showed no signs of any "film" on the front of the lenses.

2000 SVT #674 - Check it out!

Whoever coined the phrase; "If it ain't broke; don't fix it" ~ Just doesn't get it...