My optician had warned me: Don’t expose your glasses to excessive heat. Yeah, one of those superfluous security warnings like: "Do not iron while wearing shirt." Right?

Wrong, as it turns out. I went to the sauna, reading a newspaper. The sauna had 105° rather than the advertised 90° (I should probably sue those bastards). As it turns out that was enough to produce a flurry of small cracks on the surface of my glasses. It took a while to recognize this as my glasses are usually so dirty that they always look like that. But what the fuck? A hundred degrees celcius destroy that piece of craftsmanship. I bet Leornado da Vinci made better glasses. That makes a 400 CHF fee for not listening to my optician or seeing the world in a blur. Which might not be such a bad choice after all.