Aside from the fact that companies often patent things they can't/won't/don't produce, it looks like even in the patent we have a system that allows for the ins

Aside from the fact that companies often patent things they can't/won't/don't produce, it looks like even in the patent we have a system that allows for the insertion of a prescription lens into the glasses, creating a multi-lens or multi-surface display substrate. I see an allusion to some other voltage-controlled liquid crystal technology that may be able to correct for vision issues as well, but in my opinion what we're probably seeing here is: A) inside the HMD, there exists some form of micro-adjustment mechanism that can focus the content that is being displayed. For e.g. I may have good enough vision that I don't need glasses, but my IPD is such that the display is out of focus for me specifically. That's what I imagine is happening with the main glass. Remember, with something like "everyday glasses" there doesn't exist an IPD adjustment like you'd see in AR/VR headsets, and this setting can greatly affect the crispness of the display. And then... B) for customers that require more substantial vision correction, allow them to also introduce their prescription lenses in front of that main display.