A lot of the Soviet rangefinders have diopter levers for the VF/RF window; both of mine do, though since I shoot with my glasses on, the levers mostly function to annoy me when I nudge them by mistake. That doesn't help you with reading the itty-bitty aperture numbers, though.
Originally Posted by Mike Kennedy
I think most of the shutter speed dials are asymmetric enough that you can tell where you are on them by feel ("OK, the big gap is between 1/25 and 1/1000, so two more detents past that should get me to 1/250..."), so setting and forgetting the aperture should work all right. A lot of the Soviet lenses don't have detents on the aperture ring, though, so it's very easy to accidentally change the aperture while handling the camera; you may want to seek lenses that hold their aperture settings pretty firmly, or even, I suppose, tape the ring in place while shooting.
Or you could always remember your glasses... :-) I'm lucky, in a certain sense---I'm sufficiently blind that I can't get far without them anyway, as I'm liable to mistake a dog or something for the front door and get stuck trying to open it, wondering why the doorknob keeps drooling on me. But I digress.