I got some of these that clip on to my glasses for miniature painting, and they were very nice for being able to flip on and off as needed. Looks like these come in different magnification powers, which sounds handy, depending on one’s needs.

That’s such an oddly specific north to south multi-state swath of No Data that I’d easily believe there was something going on with that particular longitude, even though that’s a completely insane thing to imagine.