What to Do With Leftover Solar Eclipse Glasses

If you’ve thought about saving your solar eclipse glasses until the next eclipse in 2024, it’s not a bad idea. The American Astronomical Society says modern eclipse glasses do not expire. If the glasses were compliant with the ISO 12312-2, and have no punctures, scratches or tears, and the filters/lenses remain attached to the frames, they will last.

Older eclipse glasses used materials that degraded over time, so they were often printed with a 3-year expiration period. That is no longer true. One manufacturer, American Paper Optics, still prints the 3-year expiration warning out of an abundance of caution.

If you don't plan to reuse your eclipse glasses, you could:

• Donate them to Astronomers Without Borders. The group is collecting glasses for distribution to other countries for future eclipses. South America and Asia will experience an eclipse in 2019. Astronomers Without Borders expects to announce details of their plan soon.
• Recycle them. Remove the lenses, and recycle the cardboard.