Can Lens-Clear lens wipes scratch polycarbonate lenses?
If they are designed for plastic they should not have any abrasives in them, so they should be safe, However if you are trying to remove cloudy oxidation from your thermoplastic /acrylic/ polycarbonate headlight lens they will not work.
It would depend on the lens. Higher quality lenses are coated with a substance to help eliminate distortion and light polution. If you look at the lenses glass and you see a multi-coloured reflection on the glass, then it is probably coated. Alcohol should not be used on these lenses. It would be better to use a camera lens specific cleaning cloth to clean them.