Regarding a comment the author made in passing:

For the increasing number of people who have cataract surgery, the eye’s lenses have ben replaced with plastic, which usually have a fixed focus. (Artificial lenses that can be focused are under development.)

My dad recently had cataract surgery and I just assumed he was getting would be a deformable lens that would give him the ability to focus again. Does anyone know why it is so hard to develop such a lens ? As far as medical breakthroughs it seems like low hanging fruit and most people over the age of 45 could benefit from such a surgery since that is the age at which our lenses begin to harden and can no longer be shaped by our ciliary muscles.