North America is full of solar eclipse glasses that are now of little use for a couple decades (sooner if you don't mind traveling a bit). And even if you were planning on saving them for the next eclipse, most shouldn't be reused after more than three years. But before you toss them, consider donating them to Astronomers Without Borders. The nonprofit collects the glasses and sends them to viewers around the world who will be in the path of an eclipse and might otherwise be unable to safely view it, NPR reports. They are also sent to educational event or public viewing event organizers.
After the 2017 total solar eclipse that was also visible in the US, AWB collected millions of glasses, and vetted hundreds of thousands that were OK to be reused. Ultimately all of them were dispensed to viewers in South America, Asia, and Africa. The site has a list of places accepting donations of used glasses. Alternately, the AP points out you can also keep and use your solar eclipse glasses to search for sunspots—"dark, planet-sized spots that appear on the sun due to tangled magnetic fields." If you are ultimately looking to trash them, Time reports you should dispose of the lenses and then recycle the cardboard frames. (More solar eclipse stories.)