My personal preference is for reading glasses (some overly strong for
normal reading, with the tradeoff of having to work very close to my
nose, as explained in my previous post) with polycarb lenses (on the
cheap from an on-line glasses outfit - much less expensive than an
optivisor, and tuned to my exact prescription and eye spacing) and a
good strong light, or two, or three. My eyes are out of whack by
differing amounts, so this is the best route for me.

If your eyes are more or less boring, plain old drug-store reading
glasses are even cheaper, and easy to try. Go set up for scroll-sawing,
put your head at a comfortable position, and measure with a ruler from
the work to your nose. Go to the drugstore and take the ruler - try on
glasses until you find the highest diopter that permits you to focus on
an object at that distance from your nose.

And the answer on strength remains "it depends". I think 5 diopters will
prove to be a bit close for scroll-sawing, at least in glasses. 2.5 to 4
would probably be a better bet.

With a big lens-type magnifier, 5 might be OK, but it would be best to
try it out before buying, in a simulated setup replicating your
scroll-sawing setup as much as possible. One downside of that type of
setup is that you cannot move your head around and still see what's
happening, which you can do with glasses.

--
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