The VISOR also caused him persistent pain, which could not be treated without interfering with the device. It can be presumed that use of a VISOR is very rare, since no other characters in the franchise have appeared with a similar enhancement, and both high-ranking doctors who served on the ship were unfamiliar with the device.
The device does not reproduce normal human vision, but does allow the character to "see" energy phenomena invisible to the naked human eye, as well as allowing him to view things at infrared and at microscopic levels. This also allowed the character to see human vital signs such as heart rate and temperature, giving him the ability to monitor moods and even detect lies. The character's special visual abilities were responsible, at least in part, for his unusually rapid advancement in rank. Twice in the series, Geordi refused to be granted natural vision, first by Q and later by Doctor Katherine Pulaski. Sometime between 2371 and 2373, before the time of the film Star Trek: First Contact, the VISOR was replaced by prosthetic implants, performing the same functions, and depicted using a combination of cosmetic contact lenses and CGI.
As of 2006, 16 blind people worldwide have had sight partially restored in a procedure where electrodes implanted in their brains take impulses from a camera to allow patients to see lights and outlines of objects.
LeVar Burton, who played the character of Geordi LaForge, disliked the VISOR prop because it restricted his peripheral vision – albeit less than its prototypes – and the constant pressure of the prop's arms on his temples caused headaches.