Eclipse glasses are indeed reusable, provided they are stored properly and remain in good condition. Here's a detailed explanation:

1. Condition Check: Before reusing eclipse glasses, it's crucial to inspect them for any damage. Look for scratches, punctures, or tears. Even minor damage can compromise the safety of the glasses and put your eyes at risk during solar observation.

2. Compliance with Safety Standards: Ensure that the glasses comply with the ISO 12312-2 safety standard. This standard guarantees that the glasses have the necessary protective features to safely view the sun.

3. Expiration Dates: Modern eclipse glasses, especially those compliant with ISO 12312-2, do not have an expiration date. This is a shift from older eclipse glasses, which often came with a 3-year expiration period due to the materials used degrading over time. However, one manufacturer, American Paper Optics, still prints a 3-year expiration warning as a precaution.

4. Storage: Proper storage is key to maintaining the condition of eclipse glasses. They should be kept in a place where they are protected from scratches, bending, or other forms of damage.

5. Usage History: If the glasses have been used extensively or have been roughly handled in the past, it might be safer to replace them.

6. Certifications: Look for certifications like ISO 12312-2:2015, CE Certified, AAS Approved, and NASA Approved on the glasses. These certifications indicate that the glasses meet high safety standards.

7. Price and Availability: Considering the relatively low cost of eclipse glasses and their occasional availability issues, it's a good idea to check the condition of your existing glasses well before an eclipse. This way, you have time to purchase new ones if needed.

In summary, as long as your eclipse glasses are undamaged, comply with current safety standards, and have been stored properly, they can be reused for viewing solar eclipses. Always prioritize eye safety and when in doubt, opt for a new pair.
Roger Sarkis
Tagged: eclipse glasses