Big screens on electronic products are hugely wasteful of detail. Despite how things may seem, we don’t see the world in uniform high resolution at all. Instead, only about 1/3 of a degree is seen by the eye in great detail and the rest is really very blurred indeed (See this for more background).
Try finding the face of a relative in an unfamiliar team photograph…you have to scan serially before detecting the individual concerned.
Today’s invention allows people to exploit this phenomenon to generate the appearance of a large screen using a very small one (such as a cellphone). Just consider one eye for simplicity. The trick is for the system to sense the net direction of movement of the eye and to shift the image displayed in the opposite direction.
Once the eye starts moving, we might have only 0.01 sec before it is looking at the edge of the cellphone window…which suggests that the motion sensing might best be done by detecting electrical signals to the eye muscles (via eg an eyepiece containing tiny inductive coils).
If the eyes are starting to move leftwards relative to the screen, the image would be moved rightwards, so that the area to which attention is being drawn becomes rapidly centred on the small screen at high resolution. In this way, the illusion is created of looking at a much bigger image through a small window -which moves effortlessly to the area in which an observer is interested.