1. A compact, remountable display device for eyewear having a head-borne frame, the display device comprising: a housing assembly having a mounting mechanism disposed to removably mount to a temple of the head-borne frame of the eyewear; circuitry disposed within the housing assembly to receive data or video signals; an electronic imaging assembly supported by the housing assembly and in communication with the circuitry within the housing assembly to produce an image; and an optical element comprising: a transparent fixture for supporting an eyepiece assembly in front of a user's eye, the fixture located to receive the image from the electronic imaging assembly and capable of relaying the image internally; and an eyepiece assembly supported by the transparent fixture to direct an image to the user's eye.