I have seen some people selling a self focussing set of eye glasses that had a sonar range finder a few years ago. Not sure if it ever took off? It seems doable with current self focussing camera tech and 2 small cams above the eye to get range and a hydraulically adjusted lens for each eye that it is doable. I am sure work is being done on this? Google shows a few. Ignore the amazon ones = Chinese junk https://www.google.com/search?q=auto+focus+eye+glasses&rlz=1...