The VISOR, acronym for Visual Sensory Organ Replacement, is a medical device used in the Federation to aid patients who have suffered loss of eyesight. The VISOR detects electromagnetic signals across the entire EM spectrum, and transmits those signals to the brain through neural implants in the temples of the individual via delta-compressed wavelengths. The result is a vastly different visual acuity, with VISOR-wearers able to see in the infra-red and ultra-violet ranges, and beyond. To normal human eyes, the images relayed through the VISOR can seem disorienting and unfamiliar.
The VISOR proved useful in unique applications from time to time.
- La Forge uses the VISOR to unsuccessfully examine the Edolord "Justice" - Using a visual acuity transmitter to sent a live video feed of La Forge's point of view oboard a damaged freighter "Heart of Glory" - see if someone is lying by tracking their perspiration (unknown}
While trapped on the surface of Galorndon Core, LaForge and Centurion Bochra were able to couple La Forge's VISOR with a Romulan 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 Enterprise-D reconfigured the VISOR to emit a hypersonic burst to incapacitate their captors. (TNG: "Starship Mine")
The VISOR also allowed La Forge to see through playing cards; however he swore that he never used this advantage to cheat during the Enterprise-D's weekly poker games.
The VISOR inadvertently caused several problems as well. When La Forge was kidnapped by Romulans in 2367, the Romulans were able to use his existing neural implants to tap directly into his visual cortex and secretly brainwash him. As the VISOR is 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 emits a shortrange 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 LaForge's viewpoint to the Duras sisters' ship. Lursa and B'Etor used the footage to discover the Enterprise's shield frequency. ("Star Trek Generations")