Certified eclipse glasses: verify them in two minutes

Why the standard matters

An EN ISO 12312-2 filter passes roughly one hundred-thousandth of visible light and blocks ultraviolet and infrared to levels safe for direct viewing. Any dark plastic can look sufficient to the eye and not be remotely safe: apparent darkness says nothing about the UV and IR getting through. The criterion is never “it looks dark” but “it complies with the standard and I can prove it”.

On the medical risks we defer entirely to the official eye-safety guidance of Spain’s IGN at eclipses.ign.es. Our job here is different: making sure you can tell a certified filter from an imitation.

The verification checklist: 6 checks

1. The literal marking “EN ISO 12312-2:2015”

   It must be printed on the frame itself, not just on the box or in the listing. Look for the exact text of the standard, “-2” included: part 2 is the one covering direct solar observation. A generic “ISO”, or a bare “CE” without the standard, proves nothing.

2. A CE mark that means something

   The CE mark must be present. Beware of the known trick: a “CE” with odd proportions can be the so-called “China Export” logo. CE alone is not enough either — the next point is what counts.

3. The 4-digit notified body

   Eclipse glasses are category II personal protective equipment (PPE): their certification requires a notified body, identified by a 4-digit number you can look up in the European Commission’s NANDO database. A serious manufacturer states that number on the product or in its documentation. If nobody can tell you which body certified the glasses, bad sign.

4. The Declaration of Conformity (DoC)

   Every PPE product sold in the EU must have an EU Declaration of Conformity available — usually downloadable from the manufacturer’s website. It identifies the product, the standard applied and the notified body. Ask for it or search for it: legitimate manufacturers publish it; counterfeits do not.

5. Manufacturer and importer identity

   The name and address of the manufacturer (and the importer, if from outside the EU) must appear on the product or packaging. “Unknown brand, untraceable seller” is exactly the pattern of the counterfeits detected in previous eclipses.

6. Physical inspection before every use

   Even with all the paperwork in order: held against a lamp (never the Sun), the filter must not let through any pinpoint of light. Discard any pair with scratches, pinholes, wrinkles or a peeling filter. With children, re-check before every use — glasses travel in backpacks and suffer.

The two external verification tools

• eclipseseguro.es — Spain’s reference verifier for checking models and brands against the consumer-protection surveillance campaign. If your glasses are listed there as compliant, breathe.
• The American Astronomical Society (AAS) suppliers list — eclipse.aas.org has maintained the international list of audited manufacturers and vendors since 2017, born precisely after the wave of counterfeits around the 2017 American eclipse. If your manufacturer is there, it is strong backing.

The winning combination: correct marking + manufacturer on the AAS list or verified at eclipseseguro.es.

Where to buy with guarantees

1. Opticians and shops with an optics department. Full traceability, an accountable person in front of you, and easy access to the DoC.
2. Planetariums, science museums and astronomy shops. Specialist sellers who have handled this gear for decades and stock AAS-listed brands. Online, Astroshop has a dedicated solar-observation category.
3. Amazon and big marketplaces, with precautions. You can buy well there, but apply the filter: an identifiable seller (ideally the manufacturer or its official distributor), a brand on the AAS list, and physical verification of the marking when the package arrives. If they show up without the EN ISO 12312-2 marking printed on them, return them immediately.

When to buy

Early — not because of sales pressure but for two documented reasons: around the 2017 US eclipse the AAS recorded stock shortages and a flood of counterfeits in the final weeks, when people bought “whatever was left”; and verifying calmly (marking, DoC, eclipseseguro.es) requires having the glasses in hand days before, not on the eve. Buying weeks ahead leaves you margin to return anything that fails the checklist.

Options that pass our criteria

The curated list below shows only real, dated data (rating, review count, certification status), verified by hand on the date indicated on each card. Affiliate links: we may earn a commission; your price never changes.

What NEVER to use

• Sunglasses, even category 4 and fully certified for normal use. Not even close to the required filtering level.
• X-ray film, photographic negatives, CDs and DVDs. The most persistent myth. They do not filter UV/IR in any controlled way.
• Candle-smoked glass, the grandparents’ method. No.
• Home-made stacked filters: several sunglasses together, uncertified dark sheets, welding glass of unknown grade (only shade 14 is considered comparable, and most lying around at home are not).
• Old eclipse glasses in poor condition. Scratched or with a damaged filter: bin them. If they are pristine and certified, the AAS considers they do not expire with time — but the physical inspection rules.
• Looking through a camera viewfinder, binoculars or a telescope with eclipse glasses on. The optics concentrate the light and destroy the filter. Instruments need dedicated filters on the FRONT of the objective, never at the eyepiece.
• Dubious marketplace listings: no brand, no standard in the description, freshly created sellers with eye-catching prices. That is the exact channel counterfeits used in 2017.

Totality: the one exception

Only inside the path of totality, and only during the seconds when the Sun is completely covered, can you look with the naked eye. The moment the first ray of sunlight reappears, glasses back on immediately.

• Glasses on during the whole partial phase, before and after totality.
• You may take them off when the last ray of photosphere disappears (the “diamond ring” marks the limit).
• The instant the first ray reappears, glasses back on immediately.
• Outside the path (Madrid city, Barcelona), there is no safe moment without glasses: at 99.9% the photosphere is still visible.

Full official guidance at the IGN: eclipses.ign.es. And keep your glasses: Spain has a total eclipse in 2027 (Cádiz and Málaga) and an annular one in 2028 (source: IGN).