The total solar eclipse is coming soon — April 8, 2024. If you’re lucky enough to be able to watch it from the path of totality, you’re going to need solar eclipse glasses to protect your eyes while staring at the sun.
Solar eclipse glasses are special glasses that block out the most dangerous parts of the solar spectrum for human eyes. When you look through them, the sun should appear as an easy-to-view yellow-orange circle. Be aware that these glasses will block out all light — so you won’t use these glasses while walking, driving or doing anything but eclipse viewing.
Read more: Need Free Solar Eclipse Glasses? Stop by Warby Parker
However, there are some bad actors out there who sell eclipse glasses that don’t actually do anything to protect your eyes from the sun. So, if you’re viewing the eclipse in any capacity this year, you’re going to want to make sure that your eyes are really being protected. Read on to find out about the steps you can take to make sure your solar eclipse glasses are legit.
For more, here’s how Solar Snap can help you take great eclipse photos.
Check the ISO number of your eclipse glasses
According to the American Astronomical Society, a real and safe pair of solar eclipse glasses should be labeled with ISO 12312-2 (sometimes written in more detail as ISO 12312-2:2015), which is an international safety standard that denotes the glasses reduce visible sunlight to safe levels and block UV and IR radiation.
Check the list of reputable eclipse glasses vendors
However, fake glasses may also be labeled as being compliant with ISO 12312-2 because, as a general rule, people are greedy, selfish and not to be trusted. To double-check the veracity of your eclipse glasses’ ISO claims, you can see if the vendor from which you purchased the shades is trustworthy in the eyes of the AAS. See its list of Reputable Vendors of Solar Filters and Viewers. Really, the safest thing you can do is pick a vendor from the above list and purchase your glasses from there, so there are no concerns about counterfeits and fakes when it comes to your eye safety.
The list also includes big-box retailers and chains where you can grab AAS approved eclipse glasses, including Warby Parker, which is giving glasses away for free starting April 1. Personally, I got my glasses from a trusted local museum, but I’ll still be checking mine to make sure that I’ll be protected.
In assembling its list, the AAS checks to make sure a manufacturer earned its ISO rating with proper, labs-based testing. It also asks manufacturers for their authorized resellers and resellers for their manufacturers. If the vendor of your eclipse shades is listed, then you are safe. But the opposite isn’t necessarily true. If your vendor isn’t listed, it doesn’t necessarily mean they are slinging counterfeits. It just means the AAS hasn’t checked them out or hasn’t been able to track everything down.
So, what are you to do if your vendor isn’t on the list? Perform an eye test.
How to test your solar eclipse glasses
If your mystery pair of eclipse glasses look pretty darn dark, that’s a good place to start start. You should not be able to see anything through them except the sun itself or something similarly bright.
What’s something as bright as the sun you can use as a test? The AAS suggests you check sunlight reflected off a mirror or a shiny metal object. If sun is behind the clouds or on the other side of the earth when you want to test your glasses, you can use a bright-white LED such as the flashlight on your phone or a bare lightbulb. The reflected sunlight or bright, white, artificial light should appear very dim through a safe pair of eclipse glasses. If you can see light behind a lamp shade or a soft, frosted light bulb through the glasses through your eclipse glasses, then you know that these glasses aren’t strong enough to stare safely at the sun.
When staring at the sun through safe solar eclipse glasses, the sun should appear comfortably bright like the full moon, according to the AAS. If your eclipse glasses are uncomfortable to use, that is also a good sign that they might not be legitimate.
