Personalized color contrast -- possible?

I want to know the perfect background/foreground color combination for me (for reading/writing). Often I spend hours at a time searching for and experimenting with new color schemes to see if I can come up with something preferable to whatever configuration I’m currently using. I generally like my background to be darker than my text, but beyond that I’m all over the map. (I know it sounds crazy, but I feel like I type faster with a light-on-dark setup.)

Is there some sort of test I can have done that will determine the optimal color contrast for my eyes? Maybe if I’m ‘prescribed’ a color scheme I finally can convince myself that it can’t get any better and will stop looking.

Relatedly, is there a background/foreground color scheme you swear by? Let me know via Twitter or email.