Stefan Andriopoulos writes in his new book Ghostly Apparitions: “The origins of the television set was heavily shrouded in both spiritualism and the occult.”
The television was intended as an almost magical box through which we could watch distant events unfold, a kind of technological crystal ball. The very name implies that the television was first conceived as a technical device for seeing at a distance, something like the telephone for speaking at great distances or the telescope to view at great distances.
The term “optical media” dates back at least as far as popular Renaissance experiments — illusions with concave mirrors, magic lanterns, with walls of smoke and other “ghostly effects” were created by specialty devices. These were conjuring tricks, but having people believe in the illusions worked.
Medium takes on a double meaning here as the word refers both to the media — professional world of publishing and transmission — and to the medium who is psychic. The medium now acts as an intermediary between humans and the supernatural world..
Clairvoyance was part of the overall intention of the device.
“Clear vision” is clairvoyance and refers to a supernatural ability to see things at a distance or before events even happen which is an easy metaphor for this new mechanism. Think of remote-viewing.