Eclipse Viewing Glasses
All the specs you need to know before you purchase
Solar eclipse viewing sunglasses (buy)
Standard Issue
WARNING: It is never safe to look directly at the sun without one of these special glasses
The most important thing to watch out for is the ISO rating. NASA approved the rating to be ISO 12312-2. You pretty much have to trust the fact that the manufacturer did the expensive dirty work and tested them with a spectrophotometer. If they did, they would have the ISO logo on the glasses. If they don’t, DO NOT use them.
Don’t try to outsmart these lenses. If one of the smartest people to ever walk the earth, Isaac Newton can screw up and blind himself for three days, it might be better just to spend the money.