Where can you buy certified eclipse glasses and how can you check that they are certified?

The best and safest place to buy them is from specialist shops selling astronomical equipment or reputable opticians. To check that they are certified, make sure they are stamped with the ISO 12312-2:2015 certificate and the European CE mark, the manufacturer’s logo and the instructions. You can find full details on how to avoid counterfeits in this document: Quality criteria for eclipse glasses.