OK a little off topic, but for you bifocal wearing pistol shooters out there, have your optician make a pair of glasses with your near vision prescription for the entire lens for your dominant eye... raise the bifocal line up a couple of millimeters in your non dominant eye...it will take you about 30min to get your depth perception with the monovision arrangement but your brain corrects... you will be able to see front sight, even with scope...I use regular bifocals to shoot 5 stand and sporting clays

I carry two pair in my shooting box in the car, and if things turn bad in a hurry, I'll probably need the shooting glasses