I use a couple of Optivisors with lens plates #3 & #4. #3 is good for carving. I use #4 for engraving and watch repair. If you wear glasses for close work, it is best that you wear them with the Optivisors, but it is not always necessary. If you do, single vision lens will be better than progressives It is sometimes difficult getting the object you want to see in focus with progressive reading glasses. I have some single vision reading glasses that are almost good enough to engrave with them alone. When you combine them with a #4 Optivisor, you have to get within a few inches of the object.