Hi, we tried a polarising screen film from one of our pc monitors but you can only get them in smaller sizes as far as I know-it did the job to an extent but was far from perfect.
We also tried a protective overlay from Unicol, it is a perspex overlay with a slightly ground glass appearance to it. Didn't really help and made any text on the screen look fuzzy.
The screens themselves have an anti reflective coating as supplied and in the end after some further experimentation we found the original surface gave the best overall results after all.