Screenless video

Screenless computing systems can be divided into three groups: Visual Image, Retinal Direct, and Synaptic Interface.

In these cases, light is reflected off some intermediate object (hologram, LCD panel, or cockpit window) before it reaches the retina.

Google has proposed a similar system to replace the screens of tablet computers and smartphones.

Retinal Direct systems, once marketed, hold out the promise of extreme privacy when computing work is done in public places because most snooping relies on viewing the same light as the person who is legitimately viewing the screen, and retinal direct systems send light only into the pupils of their intended viewer.

While such systems have only been implemented in humans in rudimentary form - for example, displaying single Braille characters to blind people – success has been achieved in sampling usable video signals from the biological eyes of a living horseshoe crab through their optic nerves, and in sending video signals from electronic cameras into the creatures' brains using the same method.