You can toss, keep, or donate your 'gently used' glasses now that the eclipse is over

You might be wondering what to do with your pair or pairs of ISO-certified solar eclipse glasses now that the once-in-a-lifetime celestial event is over.

These special glasses not only kept your eyes safe, but also gave you the opportunity to “comfortably view” the last total solar eclipse that will be visible from Texas and the other 47 contiguous U.S. states until August of 2044. 

You can conserve your ISO 12312-2:2015 specs for the next celestial phenomena or dispose of them responsibly. The choice is up to you.

Schools, libraries and even Astronomers Without Borders partners are probably your best bets if you are thinking about donating your "gently used" pair or pairs of glasses.

After the eclipse, we'll have posters and framed prints from Statesman photojournalists available at usatodaystore.com.

Here’s what you should know.

Can solar eclipse glasses expire? Can I keep reusing them?

You are more than welcome to keep using your eclipse glasses for the foreseeable future IF and only IF they follow these hard and fast rules. (They also don’t technically expire.)

In order to continue to use your glasses “indefinitely,” they must adhere to the “transmittance requirements of the ISO 12312-2 safety standard” and “aren't scratched, punctured, torn, coming loose from the frame, or otherwise damaged,” according to reporting by the Pensacola News Journal, part of the USA TODAY Network.

"Furthermore, you may look at the uneclipsed or partially eclipsed Sun through them for as long as you wish,” the American Astronomical Society website states.

The materials currently used in eclipse glass production are way more durable than the materials used in the last 10, 15, or 20 years, Rick Fienberg, AAS solar eclipse task force manager, told the News Journal.

“Most manufacturers would print on their glasses, 'Discard after three years.’ That was because the materials being used in the lenses in those days did degrade over time,” he said.

Warning labels are still printed on the glasses, even though they are made with more durable materials. American Paper Optics, one of the largest eclipse glasses companies, said they print the warning to “be on the safe side.”

What’s the best way to keep my eclipse glasses in good condition?

The best way to ensure your eclipse glasses can be used long-term is to take good care of them.

Make sure you keep your glasses “flat” and “stored” in a place where they won’t be scratched or damaged, according to the Pensacola News Journal.

The AAS advises space enthusiasts to “keep them in an area that is room temperature,” so either in the package they came in or "in an envelope or other container that will keep them clean and dry and protect them against scratches and punctures."

"If you open it up five, 10 years later, for another eclipse and you see that there's no pinholes, no scratches, no tears, no rips, no delamination of the lenses or any other obvious damage, they're almost certainly OK," Fienberg told the News Journal.

If you want to keep your glasses clean, be sure wipe them with “microfiber clothes or any soft, abrasive tissue or cloth,” according to the News Journal. Wet wipes, water, or any other liquid cleaners are a huge no-no because if the paper/cardboard gets wet they could become “dangerous to use.”

This article originally appeared on USA TODAY: What do I do with my solar eclipse glasses? What to know about disposal, donation