Think of these frames as a bigger serving of the classic D2s. The D1 has been updated und upsized witha larger fit resulting in even wider peripheral views through its cylindrical lens.
The dark smoke lens eliminates the harshest of sun conditions. Reduced mirroring prevents the early fatigue of the eyes.
The mission statement of the Dragon Alliance is to support the best athletes with the best products. Thankfully for the rest us, Dragon Optics make goggles, sunglasses and accessories which are polished to perfection.