In news that surprises no one, demand for eclipse glasses has spiked, given the attention of the upcoming Great American Eclipse set for Aug. 21, which will run across the continental United States.
Considering that demand, the American Astronomical Society has updated its safety advice “in response to alarming reports” of unsafe eclipse-viewers popping up online.
So in short, you’ll want to be wary of knockoff glasses, the AAS said.
Here’s the deal: Glasses that are safe for directly viewing the sun must meet the standard, set by the International Organization for Standardization, and the glasses or viewer will then indicate that they are ISO 12312-2 compliant.
But the American Astronomical Society is now saying such a label is no longer adequate to verify glasses’ safety. So, you can’t just look for the ISO logo anymore and assume your glasses are safe.
It seems as though some companies are printing the ISO label and a fake certification on knockoff glasses that won’t protect your eyes. Some sellers are even printing fake test results on their websites, claiming the glasses are safe. But they’re not.
Experts recommend being careful when it comes to buying glasses or viewers through a third-party seller, such as Ebay or Amazon.
So, how can you tell if your solar viewer isn’t safe?
We’ll say this: The only thing you can see through a safe solar filter from a reputable vendor is the sun itself. So, if you walk through your house and you can still view ordinary household lights through your eclipse glasses or handheld viewer, then that means your device is bogus.
Solar filters that are safe produce a view of the sun that is comfortably bright, in focus and surrounded by black sky. If you glance at the sun through your glasses, for example, and find it uncomfortably bright, out of focus and surrounded by a murky haze, they’re no good.
If that’s the case, experts recommend that you should contact whomever sold you the filter and demand a refund or credit for a return, then buy a replacement from one of the sources listed on the AAS’s reputable-vendors page.
Finally, consider your source.
If you got your glasses or filter from somewhere such as a library, a science museum or a planetarium, you’re probably safe. Any reputable vendor or organization isn’t going to be giving away bogus glasses.
Any reliable source will sell or give you the correct glasses with an ISO logo and a statement attesting to their ISO 12312-2 compliance.
The only advice on what NOT to do is as follows: Don’t search for eclipse glasses online and buy whatever comes up in the ads or the early search results -- at least, not without doing some homework first.
Instead, check the AAS’ list of reputable vendors and buy from one of them.