WARNING- THIS MAY DESTROY YOUR SPECIFIC LENSES and THE VAPORS MAY KILL YOU.
Ahem, now with that said, I have seen experts remove scratches from ANNEALED, UNCOATED optical polycarbonate using the vapors from boiling Methylene Chloride. However, the "hardcoat"applied to most polycarbonate lenses tends to interfere with this method.
There are scratch repair kits for aviation visors and canopies that might do a good job for you.