I've purchased two pairs of Rockler's "Bifocal Shop Safety Glasses." The
glasses fit well and the optical corrections seem pretty good, but there's a
major bummer in the product.
The plastic hinges that connect the adjustable ear paddles to the lens are
incredibly feeble. I've bought two pairs; on both pairs the hinges have
broken after a few hours of use, leaving tiny little plastic shards that are
far too tiny to glue. One pair fell apart when I pulled the glasses out of
the pocket in my shop apron. I don't know how the second pair failed, it
just fell apart when I picked it up off my bench (although I'm pretty sure
it was not subjected to any major trauma).
Woodcraft's catolog has recently started carrying a similar-looking product,
I have no idea if its the same manufacturer w/ the same problem.
Anyway, buyers beware. I'll let you know how the returns go.