The eclipse glasses business: cardboard and inflated prices

The eclipse glasses business: cardboard with a gold-plated price tag

Twenty pairs for four quid. That's what one forward-thinking buyer paid for "certified" eclipse glasses. At about 20 cents a pair, the deal looks like a bargain, but it hides exactly what you antiestéticar: cardboard with silver paper and a mark nobody has verified. Distrust of these products is nothing new, but every astronomical event renews the doubt.

The mark that guarantees nothing

ISO 12312-2 is the standard that certifies a safe solar filter. The problem is that the label can be printed at any print shop. A batch of aluminised cardboard made without any quality control can reach the market with the sticker already on it. There are serious manufacturers, such as Baader or Thousand Oaks, but telling them apart from ordinary cardboard is beyond the average buyer.

The free alternative: a shoebox and a colander

Against the business, DIY. A shoebox, aluminium foil, a pin and a sheet of white paper are enough to project the eclipse without looking at the sun. If you don't have a box, a kitchen colander produces the same effect on the ground. Zero euros, zero risk. The welding mask option, though reliable, has a catch: electronic models darken for a few seconds, and nobody guarantees they will last through the four minutes of the event.

The baffling figure comes from the forward thinkers: 20 pairs for 4 euros. So cheap that it's impossible to trust, and so simple that perhaps the only essential thing is a shoebox. Your eyesight is priceless, but the cardboard certainly isn't worth what they're asking for it.