Janice,
I assume you are already wearing sunglasses? I also have contacts, but rarely have the dry eye problem. My sunglasses fit fairly tight to my face and seem to keep the wind out quite well. Could you find a pair that wraps around your head to keep out as much wind/air as possible? It might help your eyes stay lubricated. Can't tell anything about the RX sunglasses....... never went that route.
annie
Time is a companion that goes with us on a journey. It reminds us to cherish each moment, because it will never come again. What we leave behind is not as important as how we have lived." Captain Jean Luc Picard