I agree. For years I coded in tiny, non-anti-aliased fonts. Recently I switched to an anti-aliased font at a larger size and the difference is definitely real and positive. Less headaches, easier readability, more distance between my eyes and the screen. Also, make your fonts brighter but maintain a medium level of contrast with the background.

I heavily disagree though that larger fonts cause you to write shorter methods. That's kind of ridiculous.

A bigger font is better for your upper back, too. Take a look around you and notice how many of your fellow developers--or anyone working with text at a computer--slouch forward every few seconds to peer at the monitor. Then notice yourself doing it. Bye, bye, chiropractor.

But how big is too big? I originally coded in Monospace 10. I tried to go 14 but I just found it unpleasantly big. What fonts can you recommend?

I use 14, I find it quite comfortable.

or get a monitor arm and lean back. I got one of these http://www.lcdarms.com/products/LCD_Radial_Arms/iLift.html . It has been really nice. I almost have my monitor positioned about like the light at a dentist's office.

Hadn't even thought to do this and loving it so far today.