Want to watch the solar eclipse on August 21? If yo do, astronomers are warning to make sure the special eclipse viewing glasses you use are legitimate.
The American Astronomical Society says counterfeit knockoffs may not be safe for your eyes — and staring at the sun with them could cause damage you may not even realize until later.
AAS spokesman Rick Fienberg said many of the glasses being sold on Amazon are not certified as safe. “Apparently, the market is being flooded with counterfeits and fakes,” he told South Carolina Radio Network. “The problem is: we don’t know if they’re safe, because they haven’t been properly tested. All we know is that, because they haven’t been tested, we can’t say for sure that they’re safe.”
Fienberg said it can be difficult to tell the difference between authentic and counterfeit glasses, so he recommends using an existing list of reputable sellers. Traditionally, a customer could look for the International Organization for Standardization’s (ISO) label indicating the product met its international safety standard. But Fienberg said some counterfeiters are now copying the same ISO certification logo 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.
He said users should not be able to see anything through a safe solar filter except the Sun itself or something comparably bright. And, even then, it should appear quite dim through a solar viewer. If you can see lights of more ordinary brightness through your eclipse glasses, that may be a sign it is not legitimate. Safe solar filters produce a view of the Sun that is comfortably bright, in focus and surrounded by dark sky. Signs of improperly filtered viewers include uncomfortably bright views that are also out of focus, and/or surrounded by a bright haze.
Most of South Carolina will be able to see the eclipse in totality. The path will run from the North Carolina border near Mountain Home, through AIken and Columbia, then down to communities northeast of Charleston.
If you bought or were given eclipse viewers at a science museum or planetarium, or at an astronomy trade show, Fienberg said you’re almost certainly in possession of ISO-compliant filters
The AAS emphasized it is perfectly safe to look directly at the Sun during the brief total phase of the solar eclipse (“totality”), when the Moon entirely blocks the Sun’s bright face. However, the glasses present the only safe way to look directly at the Sun during the partial eclipse process, as the Moon slowly crosses into the Sun’s path.
Always inspect your solar filter before use; if scratched, punctured, torn, or otherwise damaged, discard it. If you normally wear eyeglasses, put your eclipse glasses on over them. Stand still and cover your eyes with your eclipse glasses or solar viewer before looking up at the bright Sun. After looking at the Sun, turn away and remove your filter — do not remove it while looking at the Sun. And do not look at the uneclipsed or partially eclipsed Sun through an unfiltered camera, telescope, binoculars, or other optical device.
Some eclipse glasses and solar viewers, even new ones, are printed with warnings stating that you shouldn’t look through them for more than 3 minutes at a time and that you should discard them if they are more than 3 years old. Such warnings are outdated and do not apply to eclipse viewers compliant with the ISO 12312-2 international safety standard, which was adopted in 2015.