Sensitivity to light causes problems ranging from mild discomfort to epilepsy. We are all sensitive to excessive light, and the flicker of fluorescent light is a hidden problem for many people - I recently saw it listed as an aggravating factor in autism in The Horse Boy. We spend a lot of time in front of computers, but I know of no research comparing the qualities of different types of monitor - I will update this as and when I hear of any.
I've just changed an ASUS MS236H monitor, that I'd had for around three years, and which I'd always found harsh, even on a low setting, for an HP Pavilion 22xi. Both have the same screen size, but the HP is much more comfortable for me to use at all settings. It seems to have some kind of anti-glare element on the screen, but I can't tell what it might be. I'll ask HP. In the meantime, if you find looking at a screen uncomfortable, consider this one, and don't hesitate to get in touch with any results. I bought mine from John Lewis for £129, including a two-year guarantee. Other monitors are available - if you have a good one, please reply to this posting.