[sfrances]

Polorized lenses are best when made out of glass because of the polorizing process. They take a lens slice it in half rotate one side 180 deg and reglu. I hava never realy seen a difference between plastic and glass. Mine are prescription and glass ( only way I can get them), I have used the cheapy plastic ones at cvs and about the same only diff is at certain times of day. If questioning wether or not a pair are polorized look at a LCD on a gas pump or something like that it should either become invisible or just rainbow same affect on auto glass you will see the tempering spots. Hope this helps more than ya barganed for I bet