glass specification for LCD 15 inch monitor

[newnewgen]

Hi,
I am looking for glass to place infront of my computer monitor, which is LCD 15' inch. The brightness is very heavy for my my eyes, even after adjusting the contrast to 15.

Please suggest the glass type(Thickness, etc) to place before my monitor, so that radiation can be adjusted.(please don't suggest the ready made screen guard found in the market)

Thanks in advance

regards
new