I am looking for something that works 24/7 so that I have my 'shooting glasses' on if the SHTF. I first tried (about 3-4 weeks ago) a set of regular gold metal frames from Lenscrafters using my distance vision correction with an inverted bifocal section for my gun sight distance, I think they called it a '35' which is wider than the std, at the top of the glasses. The idea being that you would automatically be using the top or gun sight correction whenever you tilt your head forward/down when sighting a handgun. I had him keep the bifocal up as high as possible so it woudn't interfer with my normal distance vision. Seemed like a good idea. Upon receiving them I found the line across the upper middle part of the lens is distracting unless you are real snooty (that is supposed to be a joke because your have to keep your nose up in air to keep it out of sight). I also discovered that I didn't automatically find the sweet spot for the gun sights. I would start an IDPA stage with my head down and looking through them correctly, but when I took my eye off of the target when moving or mag changing I had trouble finding it again. I feel that will be automatic, but will take some practice to get there. I went back and had them build me another pair with the shooting prescription on the entire lens, but reading bifocals in the regular position. I can easily find the sights with a slightly out of focus target and they should work fine for games. I had an old pair of glasses set up so that I have plano right eye, corrected left eye and reading bifocals. I guess I should state that I had the cartaract removed from my right eye just prior to this exercise and it is 20/20 distance, the cataract in my left eye was removed several years ago and it is about 2 diopers nearsighted. I am still looking for a panacea for old shooters. There is a fellow in NoCal that makes shooting glasses with the 'sweet spot' at the inside bottom portion of the lens. Note that one consideration for me was the desire to be able to shoot right and left handed using both eyes open, but the dominate eye would be the the right for right hand, left for left hand. All of my glasses have been polycarbonate, uv protected for years. Glass lens are too heavy for me. The polycarb lens are considered strong enough for industrial use and do not need to be drop tested like the glass ones do, at least that was true in CA when they first required all glass lenses to be drop tested, ie dropping a steel ball of a given diameter on the lens from a set height. Sorry about the 'book', let us know what works. Jim