Are Your Solar Eclipse Glasses Fake?

SonicSpike shares a report from Scientific American: A day after the American Astronomical Society (AAS) announced that there were no signs of unsafe eclipse glasses or other solar viewers on the market in early March, astronomer and science communicator Rick Fienberg received an alarming call. Fienberg is project manager of the AAS Solar Eclipse Task Force, which is busy preparing for the total eclipse over North America on April 8. He's the creator of a list of vetted solar filters and viewers that will protect wearers' eyes as they watch the moon move in front of the sun. When a solar eclipse last crossed a major swath of the U.S. in 2017, Fienberg and his team spotted some counterfeit glasses entering the marketplace -- imitations that distributors claimed were manufactured by vetted companies. Testing at accredited labs indicated that many counterfeits were actually safe to use, however. This led the task force to describe such eclipse glasses as 'misleading' but not 'dangerous' in a March 11 statement meant to reassure the public.

But then Fienberg's phone rang. The caller was 'a guy who had bought thousands of eclipse glasses from a distributor who had been on our list at one point,' Fienberg says. 'Those glasses were not safe. They were no darker than ordinary sunglasses.' Legitimate eclipse glasses are at least 1,000 times darker than the darkest sunglasses you can buy. Fienberg contacted Cangnan County Qiwei Craft, a Chinese factory that he knew manufactured safe glasses and had -- in the past -- sold them to the distributor in question. But this time, Fienberg says, factory representatives told him they hadn't sold to that distributor in a long while. 'That's when we switched from being concerned about only counterfeits to being concerned about actual fakes,' Fienberg says. The AAS does not have a confident estimate of how many fake or counterfeit glasses are for sale out there. And though Fienberg doesn't think this is a widespread problem, the situation is an 'iceberg kind of concern,' he says, because there are likely more examples than the ones he knows about. While counterfeit glasses may still be safe to use, completely fake glasses could put wearers in serious danger.

While lab tests are the best way to determine whether glasses meet the ISO standard, Fienberg says there is a three-part test people can do at home if they're concerned their eclipse viewers aren't up to the task. First, put your glasses on indoors and look around. The only things you should be able to see are very bright lights, such as a halogen bulb or a smartphone flashlight. Then, if the glasses pass the indoor test, bring them outside -- but don't look at the sun just yet. Look around: it should be too dark to see distant hills, trees or even the ground. If that second test is passed, keep the glasses on and quickly glance at the sun. You should comfortably see a bright, sharp-edged round disk. If your glasses pass all three tests, they are probably safe to wear. Still, Fienberg points out that it's best to use them for only a few seconds every minute or so during the eclipse; this cautious approach is how they're intended to be used. And if you don't trust your glasses for April's celestial event, you could try to find a reliable pair in the next two decades. 'You only have to wait 20 years for another really good eclipse year in the [United] States,' Fienberg says.

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