If you go to choose prescription sports glasses, you should have an eye exam first to get your prescription and the frame size. Then you can either get your prescription sports glasses at your doctor's store or get them online with your prescription and frame size.
When you go to choose prescription sports glasses, make sure they suit you fine. You'd better choose one that can give you maximum field of vision because when you do sports, you need more vision field to observe the movements around you.
You should consider the weight of the glasses. Lighter sports glasses will make you feel more comfortable when playing sports. If you often play sports outside, your prescription sports glasses should protect your eyes from UV rays.