The VISOR, acronym for Visual Instrument and Sensory Organ Replacement, was a medical device used in the Federation to aid patients who have suffered loss of eyesight or who were born blind. The VISOR detected electromagnetic signals across the entire EM spectrum between 1 Hz and 100,000 THz and transmitted those signals to the brain through neural implants in the temples of the individual via delta-compressed wavelengths. (TNG: "The Masterpiece Society") The result was a vastly different visual acuity, with VISOR-wearers able to see in the infrared and ultraviolet ranges and beyond. To normal Human eyes, the images relayed through the VISOR could seem disorienting and unfamiliar. (TNG: "Heart of Glory", "The Enemy", "The Mind's Eye")
Geordi La Forge, born blind, was given his first VISOR after his fifth birthday. (TNG: "Hero Worship"). The VISOR he wore in 2364 was banded in silver metal with golden tines, alternating in placement from the top and bottom bands. (TNG: "Encounter at Farpoint") In 2365, La Forge began wearing a new VISOR, which had tines stretching from the top to bottom bands equally. (TNG: "The Child"). By 2373, La Forge had begun to rely on ocular implants which eliminated the need for a VISOR. (Star Trek: First Contact)
The VISOR proved useful in unique applications from time to time.
- La Forge used the VISOR to unsuccessfully examine the Edo God. (TNG: "Justice")
- La Forge also used the VISOR to examine the Crystalline Entity. (TNG: "Datalore")
- Using a visual acuity transmitter to send a live video feed of La Forge's point of view aboard a damaged freighter. (TNG: "Heart of Glory")
- To see if someone was lying by tracking their perspiration. (TNG: "Up The Long Ladder")
- To use as a tap in for telemetry from an experimental type of probe. (TNG: "Interface")
- To use as a tap in to directly input scenes into La Forge's visual cortex. (TNG: "The Mind's Eye")
While trapped on the surface of Galorndon Core, La Forge and Centurion Bochra were able to couple La Forge's VISOR with a Federation tricorder to detect a transporter beacon emitting a neutrino pulse and ultimately escape. (TNG: "The Enemy") While being held hostage on Arkaria Base, the crew of the USS Enterprise-D reconfigured the VISOR to emit a hypersonic pulse to incapacitate their captors. (TNG: "Starship Mine")
La Forge once joked that he could see through a certain type of playing card while explaining to Worf how he knew his cards. He dismissed the joke, stating that he peeks at the cards before one folds. (TNG: "Ethics")
The VISOR inadvertently caused several problems as well. Using it caused La Forge physical pain, a result of his natural senses conflicting with the artificial sensory input from the device. Dr. Beverly Crusher offered him the options of either painkillers or exploratory surgery to desensitize the areas of his brain that were being affected, but La Forge declined both because they would interfere with the operation of the VISOR itself. (TNG: "Encounter at Farpoint") When Romulans kidnapped La Forge in 2367, they were able to use his existing neural implants to tap directly into his visual cortex and secretly brainwash him. As the VISOR was capable of receiving E-band emissions, a collaborator was able to remotely control the brainwashed La Forge with an E-band transmitter. (TNG: "The Mind's Eye")
When activated, the VISOR emitted a short-range subspace field pulse. While usually harmless, it was this emission that caused Worf to shift between universes in 2370 whenever he was in close proximity with the device. The pulse aggravated the quantum flux that Worf had been experiencing after coming into contact with a quantum fissure. (TNG: "Parallels")
In 2371, Doctor Tolian Soran modified La Forge's VISOR to transmit a live video feed of his range of view to the Duras sisters' ship. Lursa and B'Etor used the footage to discover the Enterprise's shield frequency. (Star Trek Generations) How much of his visual spectrum was broadcast is unknown, as only the "visible light" region of his vision was seen on the viewscreen.
Geordi's VISOR was a reproduction of a plastic barrette which generally fits over a womans head. Scenic Artist Michael Okuda brought it one day to the production after several test models for a VISOR were produced. (Herman Zimmerman, TNG Season 1 DVD special feature "The Making of a Legend", part "VISOR")
By looking closely at some episodes, including "Home Soil", a tiny filament can be seen stretching from the VISOR prop to behind actor LeVar Burton's ear, used to keep the prop attached to his face.