mpd, I know the problem. I found contact lenses fine while I was just short sighted; once I couldn't see the map in poor light it was harder. Personally I have bifocals with a very small bit for the closeup reading, and it works fine. My glasses are pretty small too, and look quite good - I'm vain; they have to be.
But they work fine. I did try varifocals, but panicked when I tried to go into a confined area; couldn't work out how low over the trees I was! But some helicopter pilots wear varifocals, so maybe it's just a question of getting used to them. Your best bet is to find an optician who's used to dealing with pilots, explain the problems, and take their advice.