The American Astronomical Society is warning eclipse watchers to be careful where they buy the special glasses to view the Aug. 21 solar event.
“It is no longer sufficient to look for the logo of the International Organization for Standardization (ISO) and a label indicating that the product meets the ISO 12312-2 international safety standard for filters for direct viewing of the Sun’s bright face,” an American Astronomical Society news release said.
Society Press Officer Rick Fienberg said some companies are printing the ISO logo onto fake glasses and selling them, and putting fake test results on their website to make the product seem legitimate.
“It’s very easy to take dark plastic, put it in a frame and call it an eclipse filter,” Fienberg said.
Fake eclipse glasses pose a safety concern because they may not block ultraviolet light, invisible rays that are potentially more harmful to the human eye than visible light. Regular sunglasses do not block enough light to make watching an eclipse safe.
The release warns eclipse viewers not to buy glasses online. Fienberg said in a phone interview that fake solar filters are common online, including from Amazon and eBay, where the fake glasses first appeared.
Fienberg also said some brick-and-mortar retailers may unknowingly carry fake eclipse glasses. He said he discovered glasses for sale with a label from a manufacturer he knew in a general store in New Hampshire. Fienberg sent a picture to the manufacturer, who confirmed the glasses were not theirs.
The best way to find out if a pair of eclipse glasses is safe is to confirm where the retailer ordered them from and make sure they are ISO approved. A list of ISO tested manufacturers can be found at tinyurl.com/yc97zq6h.
The American Astronomical Society Solar Eclipse Task Force, a committee that works to provide reliable information to the public about the eclipse, has been checking the paperwork of manufacturers to ensure they have ISO approval before adding them to the list.
“If we don’t list a supplier, that doesn’t mean their products are unsafe,” Fienberg said in the news release. “It just means that we have no knowledge of them or that we haven’t convinced ourselves they’re safe.”
A quick way to test a pair of eclipse glasses or other solar viewing equipment is to use the glasses to look at a bright source of light, such as an incandescent light bulb, LED light or arc welder’s torch.
While wearing proper eclipse glasses, nothing should be visible except the sun and comparably bright sources of light.
The light source should be dim and in focus, like looking at the moon at night. If the light bulb is hazy, out of focus or uncomfortable to look at, the glasses are not reliable for eclipse viewing.
While the above test can rule out fake eclipse glasses, it does not guarantee they can safely block UV rays. Proper testing requires a spectrophotometer, an expensive piece of lab equipment that tests the filter with visible light, UV rays and infrared light.
The Museum of Idaho is giving away eclipse glasses free from American Paper Optics, one of the approved manufacturers. The Greater Idaho Falls Chamber of Commerce is selling the same glasses for $2.12.
The release includes other safety tips for viewing the eclipse
No eclipse glasses should be used if the filter is bent or torn. Parents should monitor children using solar filters to look at the eclipse.
Do not view the eclipse through a telescope, binoculars or camera lens, even when wearing eclipse glasses. The concentrated light can damage the solar filter, causing eye damage. To view the eclipse through any optical device, the Society recommends attaching a solar filter to the front lens.
Eclipse viewers can safely look directly at the sun only during the eclipse’s totality phase, which is expected to occur at 11:33 a.m. in Idaho Falls and last for 1 minute and 41 seconds.
Reporter Johnathan Hogan can be reached at 208-542-6746.