The part that worries me is what happens when the glasses batteries are empty. Do they get fall back to "long-distance / myopia" mode so that you can still see at at distance and able to drive?

I love tinkering with gadgets, but sometimes the manufacturers of these tech-based version forget to cover the basics before enhancing it with tech.

A good example are smartwatches. They can be filled with sensors, but they need to at least do one thing well, and that is to show time reliably.