Blinding by the sun can often be avoided by keeping the windshield extra squeaky clean. Luckily, cleaning windows and windshields is a favorite pastime of the Real SwissTM and almost as popular as Schwingen and Hornussen combined, so it's generally a problem among the naturalised Swiss and the foreigners. In other words, it doesn't really matter.
Side note:
This issue inspired Rose Royce to their first hit many deca-moons ago during a visit here. You could go as far as saying that Switzerland made them great.
Now, if only there was a way to make them great again...
Only just saw this - and wonder if it‘s a Jura thing. Sunglasses strike me as quite common among Zürcher, behind the wheel or otherwise. (There, it’s the opposite: I sometimes wonder at those who wear mirrored glasses in the dusk or dark.) In the Jura, they do things their own way. If you‘re newish to Switzerland, please look into their history (a good search term is „béliers“). Before they got a canton of their own, there were gangs and bombs and farms set on fire. Probably the closest thing to war around here in centuries. No way are they going to put on sunglasses just because it‘s the sensible thing to do.
(Speaking of clips, there are models that come with a soft and flexible grip which won’t damage anything. You can flip them up and down. When up, it looks as though a large insect has landed on your head. Only thing that ever worked for me in tunnels. Phototropic glasses or fiddly metal clips take too long.)
I'd end up in an accident trying to switch glasses while driving. And keeping the sunglasses on is not really an option with all the tunnels and shadow regions.
I'll pay attention next time I go to Zürich and compare to mountains. People watching is a hobby for me. My mom worked in anthropology for a while and I might have got infected with the bug of seeing people as research subject
The béliers is cool. Quite curious to find a bit of bauhaus inspired visual design in the French speaking part....maybe it was a 1960's thing.