We recommend ONLY purchasing solar glasses from these manufactures directly:
The only way to watch it safely is to view the partially eclipsed Sun with special solar filter glasses that block out the majority of the Sun’s light. Only certain solar filter glasses sold online have been properly certified.
A search of solar filter glasses on Amazon will pull up hundreds of companies selling products for safely viewing the eclipse. Many of the glasses are sponsored or recommended by Amazon, and claim to have been certified for safely viewing the Sun. However, some of the vendors being featured on Amazon’s website are allegedly selling counterfeit products, and it’s hard to tell which ones are legitimate.
“Some of the places they’re selling from are reputable manufacturers who we recognize and have had their glasses certified — and others are suspect,” says Rick Fienberg, a spokesperson for the American Astronomical Society (AAS), a DC-based nonprofit that’s been working with NASA on verifying certified solar filter glasses. “We do have some confirmed reports of glasses being sold on Amazon by various vendors that are not genuine and that are not made from well-known manufacturers with documented proof of their identification.”
To properly view the Sun lead up to and following the eclipse, you need solar filter glasses that are in good condition and meet the standards set by the International Organization for Standardization, or ISO. If a solar filter is ISO certified, that means the product is well made and that it blocks all but 1/100,000th of the Sun’s light, according to Fienberg. In other words, more than 99.99 percent of sunlight will be blocked when looking at the Sun. For comparison, ordinary sunglasses only block about half of the Sun’s light.
In addition to blocking visible light, solar filters block light we can’t see, such as ultraviolet rays that can damage the skin, as well as infrared light. The lenses for these glasses are typically made of black polymer, a type of plastic made from resin infused with carbon particles. Other glasses use polyester film that’s been coated in aluminum or some other type of metal. These materials aren’t exactly easy to come by. “There are not many places in the world where the material that meets that specification is produced,” says Fienberg.
As of now, NASA and AAS only recognize five manufacturers with glasses that meet the proper ISO standards: Rainbow Symphony, American Paper Optics, Thousand Oaks Optical, TSE 17, and Baader Planetarium (the products with AstroSolar Silver/Gold film only). The products from these companies must have the manufacturer’s name and address printed on the glasses, as well as a mark saying they meet the ISO 12312-2 international standard. NASA and AAS aren’t actually testing these glasses themselves, though. Instead, the organizations are verifying that the companies that make these solar filters have tested their products at an accredited lab and have the proper documentation that says the glasses are ISO certified.
“Eclipses come around every couple of years, so we don’t have the capability to fulfill multi-million [orders of] glasses to the masses, so we have to rely on companies like Amazon,” says Lunt. He just wishes there was a way to discern the real ISO-certified lenses from the fakes.
For now, the best bet is to buy solar filter glasses directly from the five manufacturers listed on the NASA and AAS websites. Fienberg recommends shoppers bypass Amazon entirely: “Amazon is not an expert in astronomy or solar eclipses.”