Originally Posted by HarryT
In all seriousness, Neal, I'd suggest that you put this project on hold and go and see an optician. The issues you describe are not normal. It sounds as if you either need glasses, or else the prescription of your existing glasses is wrong for your eyesight. I've been sitting in front of computers for about 3x longer than you have, and I've learned that headaches are a sure sign that I need new glasses.
First step: go see an optician.
Second step: grow younger.
I.E: It may just be the natural effects of aging. But unless you want to stop aging....
My own background - I have been looking at computer monitors since some smart-ass salesman came in with a 'glass' replacement for my teletype machine.
The above suggestion to keep the light levels and contrast levels of your display similar to the background surroundings is a good one. (Reflective displays naturally do this.)
Also, look up from the screen so your eyes can focus at a different distance frequently.
The body evolved where everything is at varying distances, not just 18 inches in front of your eyes 18 hours a day.