I’m a part of the lucky few who will be witnessing this year’s total solar eclipse (and I was a part of the lucky few who witnessed 2017’s total solar eclipse). One of the things I’m doing to get ready for this year’s eclipse is making sure I’m taking good care of my eyes while I view the eclipse. It’s no secret that staring at the sun is very, very bad for the health of your eyes. And if you want to see all of the eclipse action, you do need to stare straight at the sun.
Enter solar eclipse glasses. These 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 look like an easy-to-view yellow-orange circle. Do note that these glasses block out all light — so I wouldn’t recommend using these glasses while walking, driving or doing anything but eclipse viewing.
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 and how to find solar eclipse glasses.
Check the ISO number
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.
Reputable vendor research
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.
Eclipse glasses eye test
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.
