Seeing I to I
Looking someone in the eye requires zero latency and quality optics. Looking someone in the eye (and having your eyes looked upon by those eyes) is an intimate, telepathic experience. There is no method that I know of that really duplicates this experience.
This sketch shows an “I to I” device with a transparent screen that shows the remote user’s face. Two cameras behind the screen pretend to be the remote user’s eyes (high precision motor control to mimic eye movements). When the local user looks into the remote user’s left eye, the screen will show a feed from a camera at the remote end such that the remote user’s gaze is directed into that camera. Two cameras at each end allow one to move in such a way so that you can instantly look into either eye, and there is a camera already in the right spot.