I just know that ProLens is where you'll find the best selection of Dragon goggle replacement lenses. They carry lenses for all Dragon snow goggles to include the Dragon Mace, Dragon Dx and the Dragon APX, and offer a wide variety of lens tints to suit your every day skiing and riding needs. Moreover, I find another online shop which can also replace the Dragon snowboard goggles lens. The online store is backcountry.com, you can have a try.
I've made a research that you can get dragon snowboard goggles replacement lenses at Tactics boardshop which they promise that fast, free shipping. No sales tax. Authenticity and lowest price guaranteed. Moreover, you can also find dragon snowboard goggles at Amazon as well.