While these are light enough to forget they are on your face while riding, this feature combined with moderate flexibility of the one piece lens almost make the substantiality questionable when considering the price. This is however my first pair of cycling glasses, the only comparably priced eye-ware I can compare these to would be a few models of RayBans which feel worth what you pay.
This flexibility makes changing the lenses a bit scary at first, but there seems to be a bit of technique and perhaps the lens attach points loosen up as time goes on. There has been a time or two when i had to set these down to try the lens change later, as my hands became sore and I was fearful of snapping something. The frames seem tough enough to handle this likely user error.
Coverage, visibility, and comfort are all non issues as these glasses excel in these departments. The corners of the frame disappear in your peripheral sight and the nose support is only barely there if you look down for it. The tint shift is both functional and very cool.
