These solar eclipse glasses won’t scorch your eyeballs, experts say

According to NASA, solar eclipses occur up to five times a year. However, where you are will determine whether you can get in on the astronomical action. Well, you’ve probably already heard the buzz: a solar eclipse will be visible from the US on Monday afternoon, April 8, and now’s the time to get ready.

While everyone in the lower 48 states will be able to see at least a partial solar eclipse, people in several states will be treated to something much more dramatic: totality, when the moon completely blocks the sun. This path of totality crosses Texas, Oklahoma, Arkansas, Missouri, Illinois, Kentucky, Indiana, Ohio, Pennsylvania, New York, Vermont, New Hampshire and Maine, NASA says. The action kicks off in Texas at 1:27 PM CT and ends in Maine at 3:35 PM ET.

A total solar eclipse is a big deal, and it’s understandable that you’ll want to be part of the spectacle. But you’ve probably heard that staring at the sun can seriously damage your eyes – and that’s true. “It is not good to look directly at the sun at any time,” says Aaron Zimmerman, clinical professor at The Ohio State University College of Optometry. “The sun is so bright that permanent damage to the retina (the back of the eye) can occur if you look at it for too long. And too long can last for seconds.”

Your eyes can recover from very short sun exposure (less than a few seconds), Zimmerman said. But brief glimpses of the sun can also add up. “With eclipses lasting two and a half hours, a few glimpses can add up to a significant amount of exposure,” he said. And “there is no known cure for vision loss due to eclipse.”

The good news: You don’t have to sit back and twiddle your thumbs while this impressive event takes place above you. Special solar eclipse glasses allow you to view the action safely. But since knockoffs are inevitable, choose carefully.

What are solar eclipse glasses?

Solar eclipse glasses block all but a small portion of the sun’s UV, visible and infrared light, transmitting only a safe amount that provides a comfortably clear image, says Richard Tresch Fienberg, project manager with the American Astronomical Society Solar Eclipse Task Force and co. -author of Astronomy for Dummies.

“Typically, solar filters allow somewhere between about one part in 100,000 (that’s 0.001%) and one part in 2 million of the sun’s visible light to pass through, creating a solar image that is only about as bright as a full moon,” said Feinberg. “Eclipse glasses are at least 1,000 times darker than even the darkest regular sunglasses.”

How to find safe solar eclipse glasses

Your vision is not something you want to mess with. That’s why it’s so important to do your homework when purchasing solar eclipse glasses. “Safe solar binoculars are binoculars that comply with the international standard ISO 12312-2 for filters for direct observation of the sun,” Fienberg said.

The only way to really know if glasses meet the standard is to have them tested by an accredited laboratory, but “there are very few laboratories that are accredited to test for compliance with ISO 12312-2,” according to Feinberg. His organization has compiled a list of glasses and binoculars that meet this standard to make it easier for people to find safe, effective solar eclipse glasses.

“If you have eclipse glasses that are safe — that is, meet the ISO 12312-2 standard — then you can look through them for as long as you want without risk to your eyes,” Feinberg said. “But practically speaking, the best way to view the progress of a partial solar eclipse, or the partial phases of a total solar eclipse, is to glance at it every few minutes.” The moon moves past the sun so slowly that it’s not that exciting to watch the eclipse all the time, he said.

Zimmerman recommended comparing any solar eclipse glasses you are considering against the AAS Solar Eclipse Task Force list to ensure they are from a reputable company. This is important because there are already companies selling glasses online that claim to be certified, but are not. “The eclipse glasses should all have the International Organization for Standardization (ISO) 12312-2 label somewhere on the glasses. Make sure you find that label,” Zimmerman said.

Dazed? Here are glasses that meet that important safety standard.

Test your solar eclipse glasses before using them

You don’t want to mess with your vision. That’s why it’s a good idea to test the glasses before the eclipse. “Try checking with your cell phone flashlight or by looking at a bright light in your home,” Zimmerman said. “You should barely be able to see those lights.”

If you wear the right glasses, you should be able to view the eclipse comfortably, Zimmerman said. “If you cannot view the stages of the partial eclipse comfortably, your eclipse glasses may not function properly,” he added. If so, stop watching the eclipse immediately.

On the path of totality? You have a period of about two to three minutes when the sun is completely blocked and you can see the eclipse without eye protection, Zimmerman said. “Once the sun becomes visible again, it is considered a partial solar eclipse and you should put on your eclipse glasses,” he said.