Know what ISO 12312-2 means and why ordinary sunglasses are not safe for direct solar viewing.
Ordinary sunglasses are not safe
Direct solar viewing can cause serious eye injury. NASA recommends specialized solar-viewing protection for partial and annular eclipses; regular sunglasses are not an acceptable substitute, regardless of darkness. Verify the product and its claimed compliance rather than relying on a marketplace description.
Standard and inspection
Solar viewers should comply with ISO 12312-2. Inspect glasses for damage, scratches or punctures before each use and discard damaged viewers. Supervise children. A printed standard number alone is not a guarantee that an unknown seller supplied a trustworthy product.
Cameras and telescopes need different precautions
Wearing eclipse glasses does not make it safe to look through an unfiltered telescope, binoculars or camera lens. Concentrated sunlight requires a suitable solar filter fitted to the optical equipment. Indirect viewing, such as pinhole projection, offers another approach. Check the specific eclipse visibility and timing for your location.
Practical checklist
- Look for ISO 12312-2 compliance and a reputable supplier.
- Never use scratched or damaged solar viewers.
- Optical devices require their own front-mounted solar filters.