Glasses on, Glasses off...adjust the diopter in the camera to correct for you'reshooting eye Rx, but then your tracking eye can't see. Look up from your camera and your shooting eye can't see. Hoodman Titanium PhotoFrames are glasses built for photographers. Each lens moves independently so that you can move lens up for shooting eye and leave lens down for tracking eye. Titanium memory wire technology makes PhotoFrames strong and durable. Comfortable wrap around ear pieces ensure PhotoFrames ride securely with photographers through action sequences. PhotoFrames come with clear glass templates installed to guide your Optometrist's efforts for easy fitting of your Rx lenses.