Welder's mask (specifically a number 14 filter) is one of the recommended ways to safely watch an eclipse :)
Shade 14 is key, as common welding Masks are only Shade 5 and still cause eye damage if used
Re:Amazon recalls eclipse glasses
by convolvatron on Monday August 14, 2017 @12:19PM
(#15009836)
to be clear gas welding masks are 5, its more like wearing sunglasses.
arc welding gear is generally around 10-11.
many newer electronic helmets go up to 13/14 which is enough, you have to remember to turn up the sensitivity on the sensors so that its always dark. otherwise it will stay open at around 3-4
I don't mean to say that people shouldn't take safety seriously - just saying that it's interesting how we used homemade solution to this and don't have any (obvious) sight problems.