Living in Central Florida in a community in the middle of 5 lakes, I needed a pair of biking glasses that would 1) keep the bugs out of my eyes and off most of my face, and 2) have good peripheral sight lines.These glasses do both of these things, very well.The glasses are made of lightweight plastic and appear to be sturdy, so far. I am not rough on any item I own, so I might not be the best judge of durability, since I keep everything pristine. The glasses are not only lightweight and relatively strong, but they also are comfortable to wear. The nose piece is soft and there is a replaceable one as well. There is also a carrying case.[Original thoughts on Photochromic function]One of the things I was hoping was that the glasses would darken when the sun is up. Sadly, as others have mentioned, my glasses not once darkened, even when outside riding in bright Florida afternoon sun. This is not a deal breaker for me, as I generally am out of the house riding between 6:00 am and 6:30 am and back home before 8:00 am for work. However, it would be nice to have them darken, should I decide to ride in the afternoon more often.[UPDATE]After getting another pair of these glasses, they are indeed Photochromic and darkened. When the lenses darkened, I was still able to see everything clearly, barely noticing that the lenses had darkened. Perfect for the bright Florida sun.Because of the size of the glasses, the peripheral sight lines are not cut off, allowing almost full vision on the sides. This is also great for keeping the thousands of bugs out of my eyes and half my face, as I bike along the many Lake paths we have in our neighborhood.The glasses work perfectly for me and i use them daily...