I'm a field biologist, which means I constantly take my glasses on and off because when I'm conducting a survey I like to shield my eyes from the sun while simultaneously being able to see what I'm looking at with my naked eyes or without the glasses in the way. A good example is when I'm birding; I can't really do the binoculars-through-sunglasses thing...I can see and ID stuff fine but it's just not the same and I don't like it. It feels much more "distant" to me. So when I'm out I constantly pull my glasses on and off as I pull my binoculars up to my eyes. I have found these to be very durable so far in the three months I've been using them, and I use them virtually every day either in the field or casually. I know some people here and elsewhere have had problems with their glasses snapping and whatnot, and maybe that'll eventually happen to me, but in the meantime I pull these things on and off all the time, either from the bridge (what people are saying snaps) or at an angle from the temples, and have had no problems so far. I also tend to stick them up on top of my head or even on top of a hat, which stretches them out even more, and have had no problems other than the lenses obviously get dirty if they're sitting in my hair. I have found the clarity to be great and the polarization is fantastic. Then again, this is my first pair of polarized glasses, so I have no basis really for what to expect! They can get a little creaky sometimes when I'm opening them up but it's not a huge deal. I'm removing a star just because these things are fingerprint magnets. They get dirty super easy and I have to really work hard to clean them sometimes. On top of that I often find that if they aren't perfectly cleaned there can be a very thin purple layer on them. Not something you can see if you look at them, but if you're looking through them you (or I) definitely notice it. It's not a defect and the lenses aren't messed up or anything; it's just the fact that these have to be spotless. I would definitely recommend these glasses and, like I said, it's my job and my hobby to be outside and I put these things on and off all the time with no issues of my own.