I've had these glasses for more than 15 years -- so long that the prescription is no longer quite up to snuff: going to the eye doctor soon to get it renewed, so i can update the insert on these glasses, and use them another 15 years.
I've used them biking, mountain biking, sailing, kayaking, paragliding, mountaineering, skiing... and just for everyday use. They are comfortable to my face (medium sized male noggin), stay put on my nose, with the possibility to squeeze the nose piece to fine-tune the fit.
I have progressive lenses in the insert, that worked very well for close-up as well as distance viewing.
I _really_ like the flip-up feature: as noted by others, critical when biking for instance, and entering a dark tunnel. I can flip up the outside tinted lens, and my eyes are still protected from the wind and insects etc. by the insert, i can still read maps, gps, etc. On looooong randonneur bike rides, i only need to take one pair of glasses, or i don't need to mess up with changing lenses in the evening and in the morning. When kayaking, I can flip up the tinted lens and get a clean view of my phone or gps.
After 15 years, i can feel that the ratcheting action is a bit less crisp than when new, but it still locks fine in the up or down position.
The lenses seem pretty durable: i've never babied them, i've lost them twice in the water, only for them to be found washed up on the sandy beach a day later, and i don't notice any scratches.
