Monitor Filter / Privacy Filter Question

[manthing]

i suffer from visual fatigue.
in other words, i get eye strain and can feel tired after prolonged use of the monitor.

i have a crt monitor and i set the refresh rate at 70 Hz.
as i know if this is set at 60 Hz, i would get mega eye strain.

it is an 18" (viewable) monitor.
and i set it to either 1152x864 or 1024x768 resolution.
so nothing on screen is too small.

however, despite this, in recent times, i'm still suffering from visual fatigue.

so, onto my question: will having a computer monitor filter (privacy filter) aid my situation?

i ask as these things are moderately expensive and i don't want to waste £50 or £60 on a product that has very little benefit.

does anyone here use these filters?
have the filters made a real difference?

thanks.