Solar Eclipse Glasses Guide: How to Choose ISO-Certified Eye Protection
Everything you need to know about solar eclipse glasses: what ISO 12312-2 certification means, how to spot counterfeits, and where to buy safe eclipse eyewear.
Why You Need Proper Eclipse Glasses
Looking at the Sun without proper eye protection — even during a partial eclipse — can cause solar retinopathy, a condition that permanently damages the retina. The danger is real: after every major eclipse, eye clinics report cases of people who used inadequate or counterfeit filters.
During the 2026 and 2027 eclipses in Spain, millions of people will be looking skyward. Making sure you have safe, certified eclipse glasses is the single most important piece of preparation.
The only time you can look at the Sun without filters is during the brief moments of totality — when the Moon completely covers the solar disc. During all partial phases, you must use proper protection.
What ISO 12312-2 Means
The international standard for solar viewing filters is ISO 12312-2:2015. Glasses that meet this standard have been tested to block:
- 99.999% of visible light — reducing the Sun to a comfortable, safe brightness
- 100% of harmful ultraviolet (UV) radiation
- Infrared (IR) radiation to safe levels
When shopping for eclipse glasses, look for the ISO 12312-2 marking printed directly on the glasses or packaging. This is the only standard that matters for direct solar viewing.
What About Welding Filters?
Shade 14 welding glass is technically safe for solar viewing, but it is heavy, inconvenient, and the green tint distorts the Sun’s natural color. Shades 12 and 13 are sometimes cited but do not meet the ISO standard. If you go this route, only shade 14 is acceptable — and dedicated eclipse glasses are a far better experience.
How to Spot Counterfeit Eclipse Glasses
Counterfeit eclipse glasses are a serious problem. Before every major eclipse, fraudulent products flood online marketplaces. Here is how to protect yourself:
Red Flags
- No ISO 12312-2 marking on the glasses themselves (not just the packaging)
- No manufacturer name or contact information printed on the glasses
- Suspiciously cheap — legitimate glasses cost a few euros/dollars per pair, but anything under 1 EUR/USD should raise concern
- Scratched, wrinkled, or damaged filters — any defect can let dangerous amounts of light through
- Purchased from unknown sellers on marketplace platforms without verifiable reviews
The Indoor Test
Put on your eclipse glasses indoors. You should see nothing — complete darkness. The only light source bright enough to be visible through proper solar filters is the Sun itself (and possibly very bright LED or halogen bulbs, which will appear as a faint dot). If you can see your surroundings, the glasses are not safe.
Trusted Manufacturers
The American Astronomical Society (AAS) maintains a list of verified eclipse glasses manufacturers. Some reputable brands include:
- American Paper Optics
- Rainbow Symphony
- Thousand Oaks Optical
- Baader Planetarium (AstroSolar film)
- Solar Eclipse International
Buy from the manufacturer directly or from a verified retailer. Avoid third-party sellers on large marketplaces unless the manufacturer confirms them as authorized.
Where to Buy Eclipse Glasses for Spain
For the upcoming Spanish eclipses, you have several options:
- Online from verified manufacturers — Order well in advance. Shipping to Spain from US-based manufacturers typically takes 2–3 weeks.
- European astronomical suppliers — Companies like Baader Planetarium (Germany) offer ISO-certified solar film and glasses with shorter shipping times within Europe.
- Local astronomy clubs — Spanish astronomy societies often organize bulk purchases and distribute glasses at events.
- Science museums and planetariums — Many will stock certified glasses in the months before the eclipse.
- On-site at eclipse events — But do not rely on this. Stock may run out, and prices will be inflated.
Visit our eclipse glasses gear page for specific product recommendations and purchase links.
Caring for Your Eclipse Glasses
To ensure your glasses remain safe to use:
- Store flat in a protective sleeve or envelope
- Do not fold, bend, or crease the filter material
- Inspect before each use — hold the filters up to a bright light and check for pinholes, scratches, or tears
- Replace if damaged — even a tiny pinhole can focus sunlight onto your retina
- Keep for all three eclipses — if stored properly, the same pair will work for the 2026, 2027, and 2028 eclipses
Children and Eclipse Safety
Children are particularly vulnerable to solar eye damage because they tend to stare longer and their pupils are larger. If you are attending an eclipse with kids:
- Use child-sized eclipse glasses that fit snugly
- Supervise at all times during partial phases
- Consider a pinhole projector as a fun, safe alternative for younger children
- Practice wearing the glasses before eclipse day so they are comfortable with them
The Bottom Line
Proper eye protection is non-negotiable. Spend a few euros on ISO 12312-2 certified eclipse glasses from a trusted manufacturer, inspect them before use, and enjoy the eclipse safely. Your eyesight is worth infinitely more than the cost of a good pair of solar viewers.
Ready to gear up? Browse our complete eclipse glasses guide and recommendations.