Earlier quoted context omitted.
Well in this camp. I know there's evidence to suggest that black on white is better for reading comprehension, but I honestly find it straining. To me black on white is just a hangover from old skeuomorphic design principles.
I found that black background with white text is great when you have perfect eyesight but once your eyesight starts to go and you start needing glasses white background with black text is easier to read. it's quite odd. It could be just a personal thing though.
The bigger factor seems to be environment you are currently in:
- Fluorescent operating room/accountant's office/Initech --> white backgrounds needed.
- Darkened lab/color-correct studio/night-time --> dark backgrounds.
And of course this has gotten worse over the years as control over the gui theme has been lost.