Good sports sunglasses won't block your vision, otherwise they are useless and nobody wants to get them for sports. So I think there is no need for you to worry about this. Just choose the sports sunglasses that fit you well.
It will depend on what kind of sports sunglasses you wear. If the sports sunglasses are too small for you, it may block your peripheral view. So you'd better choose one that fit you very well, neither too large nor too small.
These sunglasses are designed for sport, so they won't block your vision, otherwise it would be pretty useless. What's more, when you look around, your head moves, too. So you don't usually only move your eyes when looking around and your vision won't be blocked.