For those of us that need bifocals I take my favorite pair of sunglasses and trim a pair of these plastic reading lenses to fit at the bottom. An inexpensive way to get to bifocals without the custom work. They attach with just water and, magical, seem to never come off. Comes in many magnification levels. Depending on your eyes you may need two different levels. Enjoy, John

https://www.amazon.com/Optx-20-Stick.../dp/B000W7HQCQ