If you can't find eclipse glasses, read this
by Doc Searls Saturday, August 12, 2017

Since there seems to be a run on eclipse glasses, here's helpful hint: head to the hardware store and get welders goggles with a rating of 14 or higher. They'll do the same thing, and many are still out there, mostly because they're not yet called "eclipse glasses." 

Look also for "brazing" and "safety." More here from Mr. Eclipse.