Yes, but once you solve those issues, you don't need a super high resolution, light field based (or otherwise adjustable focus) display that's very small and ha

Yes, but once you solve those issues, you don't need a super high resolution, light field based (or otherwise adjustable focus) display that's very small and has very high battery life, to achieve the same portability. Your face doesn't need to have a weird-looking and -feeling object on it, and if you can hook into the original eye signal, you get a free dual camera for AR. Oh, and on a less geeky note, it gives sight to the blind. The resolution and the focus will certainly be solved long before an implant could give remotely similar performance, but an implant would sure be neat for the other reasons.