Here's the video associated with the Nvidia paper on Near-Eye Light Field Displays linked elsewhere in the comments. https://www.youtube.com/watch?v=uwCwtBxZM7g It gives a very clear overview of the concept and prototypes.
It allows you to focus on near objects, and focus on far objects. It's not an infinite depth-of-field display... You visually get to chose where you focus!
It's like the DISPLAY version of a Lytro camera! (I wonder if you could hook up a one to the other!)
This is amazing!