How to avoid unsafe eclipse glasses before France's August 12 solar eclipse

Astronomy experts are warning people across France not to assume that every pair of eclipse glasses on sale is safe ahead of the rare solar eclipse on August 12.

During the solar eclipse, the moon will pass between the earth and the sun, creating a partial eclipse visible across France. The eclipse will begin at around 19:30 with its maximum coverage at around 20:15-20:30.

Although France will not experience a total eclipse, some areas will see almost all of the sun covered up with up to 99.5% of it obscured in parts of the south-west, around 97.8% in Toulouse, more than 96% in Bordeaux, Montpellier and Marseille, 92.2% in Paris and around 89.9% in Strasbourg.

However, even when most of the sun is covered, looking at it directly without proper protection can permanently damage your eyes. For this reason, people wanting to watch the rare event can purchase special protective glasses.  

However, the Association française d'astronomie (AFA) recently raised concerns about eclipse glasses distributed with a French kiosk publication, saying the product did not meet the required safety standards and asking France’s consumer protection authority, the DGCCRF, to intervene. 

What to check before buying eclipse glasses

Safe eclipse glasses should:

• Come from a reputable supplier 

• Identify the manufacturer or responsible supplier

• Include instructions for safe use

• State compliance with the ISO 12312-2 standard for solar viewing filters

A printed ISO reference alone does not guarantee that a product is genuine or traceable. Buyers should be cautious about glasses with no manufacturer information, unclear origins or sellers who cannot provide basic product details. 

Products with unusually low prices, especially from unknown sellers, should also be treated with caution.

Meanwhile, regular sunglasses, even dark ones, should not be used as they do not provide enough protection for looking directly at the sun. Eclipse glasses with scratches, tears or damage to the filter should not be used either. 

Other improvised methods, such as smoked glass, photographic film, CDs or DVDs are also not recommended. 

Finally, eclipse glasses should never be used with binoculars, telescopes or cameras. These devices concentrate sunlight and require their own specially designed solar filters. 

Previous eclipses have seen strong demand for protective glasses, sometimes leading to last-minute shortages. Buying from a reliable source in advance can help avoid problems close to the event.

You can also check how the August 12 eclipse will appear in your commune in our article here.