Any of the post-40 POA crowd use progressive lenses while flying? I've been using traditional bifocals for the last couple years based on what I've heard about potential distortion/blurring of peripheral vision. BUT, I''m finding it very difficult to get decent prescription sunglasses for traditional bifocals. Many companies that do Rx sunglasses only offer single vision or progressives. Lenscrafters will do bifocal lenses, but the colors and lens thickness are extremely limited. For those that use progressives, have you found any distortion issues?