how effective are glare filters?

i'm thinking of buying one for my 19" crt monitor. it really bothers my eyes right now if i use the comp for extended periods of time, like 3 hours or more. My refreash rate is set at 85, which is the highest, so that shouldn't be the problem.

so will glare filters help with the situation?

They are nice for deflecting glare from direct sunlight on the screen but they really grays/greens out the colors. They are pretty cheap, buy one and give it a shot for a couple of days. Return it if it does not work out.