How to Make Sure Your Solar Eclipse Glasses Will Actually Block the Sun
Despite what Bruce Springsteen says in his hit song “Blinded By the Light,” looking into the “eyes of the sun” is no fun. According to Prevent Blindness, exposure to the sun’s rays during a solar eclipse without proper eye protection can cause “eclipse blindness” or retinal burns, also known as solar retinopathy, and the damage to your vision may be permanent.
With the Moon’s next transit between Earth and the Sun expected to be at least 20 years after the upcoming solar eclipse on April 8, you may be tempted to look at the sky without proper eye protection. However, even briefly looking at the sun during a solar eclipse can cause permanent damage to your eyes. I’m not your parent, but I strongly encourage you to keep your eyes safe by purchasing a pair of solar eclipse glasses.
However, some unscrupulous third-party sellers sell counterfeit glasses through Amazon and other online sellers, which can put your vision at risk. (Just ask the California man who suffered significant vision loss from a pair of counterfeit glasses, reports the Indianapolis Star .) To keep your eyes safe and see the next day, here are some tips to help you know the pair of glasses you’re looking for wear, selected, will do their only job.
Check ISO number
To determine whether your solar eclipse glasses will block ultraviolet and infrared radiation, check the International Organization for Standardization (ISO) number on the frame. According to the American Astronomical Society (AAS), compliant glasses will be labeled ISO 12312-2 (sometimes referred to as ISO 12312-2:2015) to show that they reduce sunlight to a safe level.
Wait, the counterfeiters wrote this number there too, right?
They definitely can! To make sure you’re buying solar eclipse glasses from a trusted source, AAS has compiled a list of manufacturers, retailers, dealers and importers they’ve vetted to help you with your purchase.
While the AAS notes that they cannot investigate all sellers, they offer sage advice:
We do not recommend searching for eclipse glasses on Amazon, eBay, Temu or any other online marketplace and buying them from the seller who offers the lowest price. Before purchasing a solar viewer or filter online, we recommend that you ensure that (1) the seller is listed on the site and (2) the seller is listed on this page.
Can I just test them myself?
According to the AAS, you can use sunlight reflected from a mirror or metal object to test whether your solar eclipse glasses are working. If the reflected light through the lenses appears very dim, you may be safe. However, if you see light through a lamp, lightbulb, or other household fixture, you may have fake glasses.
Also, check your glasses to make sure the lenses are not torn, scratched, punctured, or falling out of the frame. If yes, discard them.