Edit: Of course, if you squish your glasses closer to your eye while observing, the optical shop measurement associated with normal wear will be greater than what you experience while observing. A little at-the-eyepiece experimentation with how much squishing you do to see the entire FOV with your glasses on might be helpful.
Hello David,
I actually had a pair of glasses made at the optician's that are designed only for use with binoculars and telescopes, with a magnification of 0.25 diopters higher so they sit closer to my eyes.
Unfortunately, I seem to be blessed with plenty of Neanderthal genes, so my nose is quite protruding, and I'm constantly pushing my natural limits with this facial physiognomy.
Andreas