If you ever code for hours on end with the white background, you realize how awful it is. I used to, but when my eyes started losing focus a lot more often, I knew it was time to change things up.
Honestly, I don't understand how people's eyes are so sensitive.
I don't think the colors you use matter in the slightest in terms of how long you can code.
It doesn't matter if you use dark colors or light colors.
Seriously...
Well, the compiler could care less if everything was black, as long as it was correct. I however find it very bad to stare at a glowing white screen for 5-6 hours a day.
I do it every moment that I'm not asleep, cooking or 'bathrooming.'
So, somewhere around 16 hours a day.
I have the LCD brightness on my screen turned all the way down, though. That probably makes a difference.
That makes a hell of a difference. My computer is really bright all the way up, which is how I usually have it set. I can't hardly see anything without it being up so high.
Yeah, I only feel the need to turn that up a little when there's a lot of glare obscuring my screen.
Otherwise, keeping it turned down helps with my battery life.
(And saves power when it's plugged in.)
Honest to god, I tried using a non-mono space font, and found that it was the hardest thing in the world to get used to. I immediately switched back. I did try the Death Note font once for fun, that didn't work either.
Also in this thread (somewhere), most people say you read light on dark better, although this shows it's a disputed topic. This guy says it's harder to read, but there's more discussion here.
I tried Courier New a moment ago and found that it was much smoother, but the anti aliasing made it look blurry. I love the standard Courier 10. It's compact, easy to read, and sharp.
Really interesting discussions, there.
There isn't any actual concluding answers, there, but still some useful info. (Although, I take it with skepticism.)