Just thought I share these special bifocals, for those of us who need such things in order to see and be safe too. My optician made me a pair of "electrician's" bifocals with a close up lens at the bottom and top of my large safety glasses. Now when I need to look up or under a piece of equipment I don't have to fight the bottom location of my close up lens. I highly recommend this improvment and can't believe what a difference it makes. PS make sure your safety glass lens are the high impact plastic and not glass. And my safety glasses are RED so I don't ever loose them, and I look cute in red too!(OK its a girl thing)