Off-the-wall solution: needing to be able to read broad areas of map in flight (geologic map, lots of detail), I got an 8 x 11 fresnel-lens magnifying reader, hung it from strings around neck so it is 5" above map and perpendicular to downward glance. Awkward to wear, but I can skip the reading glasses and have uniform field of view for instruments/outside world, magnification only kicks in when contemplating navel.
A possible kinky solution for those concerned about appendage size, I guess. Myself, I'm fully clothed when flying helicopters.
D