Aug. 7 (UPI) -- The American Astronomical Society on Monday warned that fake solar eclipse-viewing glasses are being sold ahead of the Aug. 21 event.
The society said not all glasses available for purchase meet international safety standards for directly viewing the sun. In the past, the AAS has warned people to make sure glasses have "ISO 12312-2" printed on them.
"But now the marketplace is being flooded by counterfeit eclipse glasses that are labeled as if they're ISO-compliant when in fact they are not," the AAS said. "Even more unfortunately, unscrupulous vendors can grab the ISO logo off the internet and put it on their products and packaging even if their eclipse glasses or viewers haven't been properly tested."
The AAS offered up a list of reputable brands and companies that sell glasses that are compliant with safety standards.
"The problem with fakes is that you can't know if they're letting unsafe levels of solar ultraviolet and/or infrared radiation into your eyes," said Richard Tresch Fienberg, a press officer with AAS. "You'd never know until it's too late, because our retinas don't have pain receptors."
NASA says glasses older than three years or that have scratches are not safe.