DS (13) plays an outdoor ball sport and needs to wear sports sunglasses when he plays. He loses or breaks at least one pair every year so I don't like to pay more than £30ish. I normally get them from Amazon, but of course it's notoriously difficult to know whether you're getting a quality product from there. DS would like his next pair to be polarised, and the prices range from under a tenner to over a hundred. Apart from just picking something that looks cool in the right price range with decent reviews, how on earth do I choose? Can anyone recommend a brand that doesn't cost the earth but ticks the boxes.