For a few moments on Monday, millions across the U.S. will don those special eclipse glasses before looking skyward to catch the first total solar eclipse we’ve had in years. But after it’s all said and done, what should you do with those special eclipse glasses?

You could stash them in a drawer as a reminder of April 8, 2024, or stash them for the next solar eclipse.

But there’s another way to prevent used eclipse glasses from ending up in landfills — donate them for reuse.

The international organization Astronomers Without Borders (AWB) has collected millions of glasses for distribution around the world. This allows people who live in the path of a future eclipse to safely view the celestial phenomena, without needing to buy a new pair for a single use, KTLA sister station KXAN in Austin, Texas reports.

AWB communications manager Andrew Fazekas said that the program began in 2017, ahead of that eclipse.

“It was so successful with hundreds of collection sites across the nation, with donations reaching in the millions of glasses,” Fazekas said. “There are a lot of underserved communities that just don’t have access to this safe eyewear. So we’ve been providing hundreds of thousands of glasses across the world, for places like Chile, Argentina, Ethiopia, Sri Lanka, the Philippines.”

Some, like the city of Austin, Texas, will have AWB recycling boxes to collect those glasses.

“[An] eclipse coming here in our town is rare, but it happens about every year and a half,” said Gilda at a city press conference on April 2. “There’s an eclipse somewhere, and not all the communities have the same resources that we have. So we’re going to share the resources that we have and make it a more sustainable experience.”

Fazekas said that the effort helps to “put a dent” in eclipse waste, but millions will still have to be thrown away.

“We probably can’t reach all of them… we are not expecting to collect all of them by any means, and many are going to be damaged,” he said. “But I think we can reach numbers in the low millions at least, and prevent those from reaching landfills. Gently used glasses are going to be well worth saving, and giving a chance for other folks around the world to experience this is a wonderful thing.”

Warby Parker, in addition to handing out free eclipse glasses, will collect them afterward and donate them to AWB. You can bring your glasses to any Warby Parker location before the end of April.

There’s also no harm in hanging on to your glasses. The U.S. won’t see another total solar eclipse until 2044, and, as long as they aren’t damaged, eclipse glasses never expire.

According to the American Academy of Ophthalmology, you can remove the lenses from the glasses and recycle the cardboard frame, if you prefer that option.