I shoot with M3 which has my 50mm 'Cron glued to almost permanently (except of the rare occasions I'm in the mood of 90mm dedication). I wear glasses also but figured 50mm frames in M3 are apparent and clearly observed without an excessive eyeball excercise, yet the frame lines are towards the edges of the frame. The lines are clearly visible (and they are quite thick and obvious, to considerably more degree then in M6).
I found it is a pure joy of focusing with M3 (either 50mm or 90mm) thanks to a large and well defined RF patch.
M6, M7 0.85, M3, 35mm 'Cron ASPH, 50mm 'Cron, 90mm Elmarit
My M3 is up for sale...
My RFF gallery
We're not famous by strength of our weapon, we're not famous by our courage, we're not known by our smartness, but we are famous by the weakness of our enemies...