Like larissa, I use Flux for eye-strain reduction, especially because I need computer-only reading glasses. Less strain on eyes = fucking win. I also use a 'zap colours' bookmarklet from Squarefree that turns all pages back to black text on white with blue or purple hyperlinks in order to make low-contrast colour schemes readable. For a while before I got my reading glasses I was Ctrl+ and Ctrl-ing text all the time, but I don't need text to be huge in order to focus on it anymore.