Solar Eclipse Glasses: Where to Buy and How to View Safely

Observing a solar phase requires certified eclipse glasses or safe projection methods to prevent permanent vision damage, as standard sunglasses provide insufficient protection against harmful solar radiation.

Safe Viewing Requirements

Solar eclipses must not be observed using ordinary sunglasses. Polarizing filters, tinted glass, and X-ray photos also fail to provide protection. Direct viewing requires specialized eclipse glasses, or alternatively, a projection method using a cardboard box as recommended by NASA.

In Poland, a partial eclipse is visible, meaning glasses or a proper filter must remain on the eyes for the entire duration of direct observation. The phase where glasses can be removed only occurs in the path of a total eclipse when the bright solar disc is one hundred percent obscured.

Choosing the Right Glasses

Safe glasses for direct solar observation must meet the requirements of the international standard ISO 12312-2:2015. Products sold in Europe may carry the marking EN ISO 12312-2:2015 and the CE mark. These specialized glasses are thousands of times darker than regular sunglasses, limiting visible light as well as harmful ultraviolet and infrared radiation.

The mere imprint of “ISO 12312-2” does not guarantee proper testing, as counterfeit products may bear the same mark. The American Astronomical Society recommends verifying the manufacturer and purchasing directly from them or an authorized dealer.

Where to Buy Eclipse Glasses

Eclipse glasses should be sought in specialized astronomical and optical stores, manufacturer-run shops, and authorized distributors. In Poland, these include Delta Optical, Teleskopy.pl, and Astroshop, offering brands such as Baader Planetarium, Bresser, American Paper Optics, Absolute Eclipse, and Omegon.

Glasses can also be found on platforms like Allegro, Amazon, or Empik Marketplace, but buyers must verify the auction description, manufacturer name, seller details, and product origin to avoid the risk of vision loss from anonymous sellers.

Inspection Before Observation

Before putting on glasses, the filter must be inspected for scratches, cracks, holes, and peeling fragments. Damaged glasses must not be repaired with tape or reused. Indoors, wearing safe glasses should render furniture, walls, and other objects invisible, with only very bright light sources appearing extremely dim.

A cardboard frame does not indicate poor quality, as safety depends primarily on the applied filter, its origin, and its condition.

DIY Box Projector Method

While ISO 12312-2 glasses are the safest direct observation method, an indirect projection method can also be used. To build a homemade cardboard box projector, a white sheet of paper is taped inside one short end as a screen, while two holes are cut in the opposite end.

One hole is covered with aluminum foil featuring a single pinhole, and the second hole serves as a viewing port. Observers stand with their backs to the Sun, allowing light to pass through the foil pinhole to project the solar disc onto the white paper screen inside the box.

Using Welding Masks

Only a fixed welding filter with an appropriate shade level may be used for solar observation, with the American Astronomical Society placing the safe range from DIN 12 to DIN 14. Filters rated at DIN 15 or higher are excessively dark, while DIN 9, DIN 10, and DIN 11 are too bright and unsafe.

Auto-darkening masks and adjustable filter models are discouraged by the AAS due to the risk of accidental lower settings or delayed reactions. The filter must be free of cracks, chips, and scratches.

Binoculars and Telescopes

Binoculars and telescopes concentrate solar rays and can cause severe vision damage almost instantly if used without a proper filter. A special solar filter must be securely mounted in front of the objective lens rather than near the eyepiece.

Risks of Improper Observation

Improper observation can cause solar retinopathy, which is retinal damage lacking pain receptors, meaning individuals may not feel the injury occurring. Symptoms can appear later, including reduced visual acuity, a central dark spot, distortions, and color perception disorders.