Have you considered using some sort of magnification while painting? A lot of folks use Optivisors or some other kind of magnifier. I personally disassembled a couple of those tabletop magnifiers with the alligator clips on articulated arms to hold things and frankensteined together a nice long articulated arm with a 5X magnifying glass on it.
One thing you can do is use your camera to check your work - take pics of the areas you're painting and make notes of where you've make mistakes, then go back and touch them up. If your camera has a viewscreen on it, keep it nearby as you work and snap pics as you go to check your work.