The American Astronomical Society (AAS) issued the following statement on August 1, 2017, prior to the August 21 total solar eclipse.
How can you tell if your eclipse glasses or handheld solar viewers are safe? It is no longer sufficient to look for the logo of the International Organization for Standardization (ISO) and a label indicating that the product meets the ISO 12312-2 international safety standard for filters for direct viewing of the sun’s bright face. Why not? Because it now appears that some companies are printing the ISO logo and certification label on fake eclipse glasses and handheld solar viewers made with materials that do not block enough of the sun’s ultraviolet, visible, and infrared radiation to make them truly safe.
Some sellers are even displaying fake test results on their websites to support their bogus claim of compliance with the ISO safety standard.
Given this unfortunate situation, the only way you can be sure your solar viewer is safe is to verify that it comes from a reputable manufacturer or one of their authorized dealers. The AAS Solar Eclipse Task Force has been working diligently to compile a list of such vendors, now posted on its Reputable Vendors of Solar Filters & Viewers page.
Task-force members have checked manufacturers’ ISO paperwork to make sure it is complete and that it comes from an accredited testing facility, and they’ve asked manufacturers to identify their authorized resellers and dealers to identify the source of the products they’re selling. Only when everything checks out does the AAS add a vendor to its listing. AAS Press Officer and task-force representative Rick Fienberg said:
If we don’t list a supplier, that doesn’t mean their products are unsafe. It just means that we have no knowledge of them or that we haven’t convinced ourselves they’re safe.
Bottom line: Be sure your eclipse glasses come from a reputable supplier, such as a planetarium, science museum or other longstanding science organization. Did you purchase eclipse glasses from EarthSky? We are on the AAS-approved list.