"I bought these as a rush purchase before a marathon when I realised it was going to be sunny. I had never worn sunglasses running before so I was nervous about using a fresh pair on a 26 mile race. My fears were unfounded because these fitted me very well and I hardly noticed I was wearing them - which, I guess, is the aim. I haven't tried changing the lenses yet, but they feel sturdy enough that it won't be a delicate affair. I've since worn them cycling and they do a good job of keeping all the grit out. Very pleased with the item and very pleased with Wiggle for getting them delivered so quickly and on time."