If you plan to look directly at the Sun during a partial eclipse, or at the bright photosphere outside totality, you need solar eclipse glasses or handheld solar viewers that meet the international filter standard ISO 12312-2 (sometimes written ISO 12312-2:2015). Regular sunglasses, photo film, smoked glass, or unlabeled “NASA-style” shades are not safe: they can let through enough ultraviolet (UV), visible light, and infrared (IR) to cause permanent eye injury.
Search demand around phrases like “ISO 12312-2 eclipse glasses” and “certified solar eclipse glasses” has spiked before every major eclipse because buyers want a simple answer: will this product protect me? This guide explains what the standard is meant to do, what to check on the product and packaging, and how to buy from sources you can trust.
What ISO 12312-2 actually covers
ISO 12312-2 applies to non-magnifying filters for direct observation of the Sun, including paper eclipse glasses and plastic viewers. It sets strict limits on how much light passes through, including visible light and key UV/IR bands, so that normal use does not deliver hazardous exposure. Products are also expected to be free of defects (scratches, holes, delamination) that could let concentrated sunlight through.
The American Astronomical Society (AAS) publishes guidance for suppliers and maintains resources for the public on solar eclipse eye safety. Always pair certified viewers with common sense: supervise children, inspect filters before each use, and follow printed instructions.
Buyer checklist: certified solar eclipse glasses
- Look for ISO 12312-2 printed on the product or instructions (not just a generic “CE” sticker without context).
- Buy from the brand store or a reputable retailer, especially before high-demand windows like the 2026 total solar eclipse.
- Inspect lenses before every session: discard if scratched, punctured, warped, or loose in the frame.
- Do not use damaged filters even “for a second”: solar retinopathy can be painless and permanent.
- Remember: eclipse glasses are not substitutes for solar telescope filters unless the product is explicitly designed and labeled for that optical system.
Counterfeits and “too good to be true” pricing
Before major eclipses, marketplaces fill with fake eclipse glasses that claim ISO compliance without verifiable testing. Red flags include missing manufacturer identity, no instructions, prices far below trusted brands, and sellers that cannot answer which lab tested the batch. When in doubt, choose a supplier that publishes conformity information and stands behind the product.
Helioclipse solar viewers are intended for direct solar viewing when used as directed. For pack sizes suited to families, schools, and events, browse our eclipse glasses collection and order early; inventory and shipping lanes get crowded close to eclipse dates.