Eye-5

Eye-5 was a special kind of contact lenses that can be used to record the things it sees. According to Jack Harkness they come from a distant moon orbiting a distant star.

Functions
The lens, though they looked and functioned just like normal contact lenses, could transmit information wirelessly back to a computer network. A person at the other end could then communicate with them via a keyboard. However, the lens could not transmit sound. (TW: Reset) To get around this, the lens had lip-reading software, which worked best when the person in question faced the camera directly. The lip-reading software transcribed lip movements to speech after a short delay of a second or two. Information transmitted from the lens could get recorded like conventional video. According to Gwen Cooper, they were also apparently untraceable. (TW: Children of Earth: Day Three) Gwen claimed to Rex Matheson that they were isomorphic and would only work for her, but she was lying. (TW: Dead of Night)

History of use
The lens were used by Martha Jones when infiltrating the Pharm. (TW: Reset) Later, after Rhys and Gwen and so Ianto borrowed them for some "fun", Lois Habiba, the secretary to John Frobisher used them to record secret negotiations between the British government and the 456. (TW: Children of Earth: Day Three) Downloaded onto a laptop, Rhys Williams then held onto the information so that he could, if Torchwood Three needed to do it, reveal the negotiations to the public. (TW: Children of Earth: Day Four) After the conclusion of the 456 crisis, Bridget Spears wore the lens to record Prime Minister Brian Green casually mentioning his complicity in the affair. (TW: Children of Earth: Day Five) Gwen Cooper used the contact lenses in 2011 to infiltrate PhiCorp. (TW: Dead of Night)


 * The interface looked slightly different on each occasion.