I was very, very impressed with Chris Vogler, the optician here:
http://www.safevision.net/shooting/index.html
He's serious about making good shooting glasses and has done so for folks with a wide range of habits. He asks a lot about your habits and use, as well as physical details. Reasonable price for prescription lenses, plus he sends multiple sample frames for only a minor shipping fee so you can try different fits. Highly recommended.