If LCD's are causing headaches and fatigue, the most likely reason is that you have your brightness at default which is usually 100%. Many people including myself are telling you to turn the brightness down to about 50%. I usually have brightness on LCD's at about 40-50% and contrast at 80-90%. For most people, this is all they need to do when adjusting an LCD. LCD's are set very bright at factory default because on the showroom floor, it looks great at full brightness. However, during normal use, it's best to dim it down if you don't want the brightness to cause headaches.
CRT's are not as easy on the eyes because most of them have at least a minor bit of flickering. This can be caused from low refresh rates to dirty power sources (my CRT's image noticeably degrades when the AC kicks on while the LCD doesn't). Where the CRT's excel is refresh rate and color reproduction.
Older LCD's had horrible response times and thus lots of ghosting that made them unsuitable for gaming. This has largely been solved in the latest LCD's. While there may still be very minor ghosting, it's not noticeable unless you've got your face plastered to the LCD and looking specifically for it. I don't notice any ghosting on my LCD's at all while gaming.
CRT's are not as easy on the eyes because most of them have at least a minor bit of flickering. This can be caused from low refresh rates to dirty power sources (my CRT's image noticeably degrades when the AC kicks on while the LCD doesn't). Where the CRT's excel is refresh rate and color reproduction.
Older LCD's had horrible response times and thus lots of ghosting that made them unsuitable for gaming. This has largely been solved in the latest LCD's. While there may still be very minor ghosting, it's not noticeable unless you've got your face plastered to the LCD and looking specifically for it. I don't notice any ghosting on my LCD's at all while gaming.