The blindness that has affected Geordi La Forge throughout his life is the result of a natural defect of the optic nerve - a condition that left him without sight during his early childhood.

First sight

Until 2371, La Forge's blindness was overcome, not through medical surgery but by a unique device known as the VISOR, which is an acronym for Visual Instrument and Sensory Organ Replacement. This remarkable feat of bioelectronic engineering bypasses the useless optic nerve and supplies information directly to the brain, enabling the wearer to see, though somewhat differently from normal human vision. The VISOR itself is not much larger than an ordinary pair of sunglasses, and is worn in a similar manner.

The VISOR attaches at the temples via neural implants that connect directly to the brain. It permits the user to see not only visible light but across an expanded range of the electromagnetic spectrum, including infrared and radio waves.

Unfortunately, for all its benefits, the VISOR is not without its disadvantages. Although the instrument allows its wearer to see, it is painful to use. The pain, though quite intense in the beginning, does become bearable as the wearer gradually get used to it, and eventually becomes more like a dull ache. Athletes often go through similar discomfort in the pursuit of their chosen way of life, and the disadvantages of wearing the VISOR are considered a worthwhile price to pay for the ability to see.

Seeing with the VISOR

The Visual Acuity Transmitter is engineered as an attachment to the VISOR, which enables others to see the same images as the VISOR wearer, including those beyond the normal human range. However, this has disadvantages. The device is successful in that it faithfully transmits the input from the VISOR to a viewscreen, but the images are virtually impossible for others to interpret, appearing as little more than a swirling mass of colors.

Indeed, the VISOR provides such a complex and broad-based input to the brain that the user must concentrate in order to focus on one area. As La Forge explained to Captain Jean-Luc Picard, the experience is like hearing all the voices and noise in a crowded room; we learn through trail and error how to filter out the unwanted sounds and to focus on a particular voice. In much the same way, the wearer can learn over time how to see a particular image out of the flood of information that is being transmitted to the brain through the VISOR. It may well be this very intense focusing ability that has enabled La Forge to master the complexities of warp engineering and other starship systems.

Superior vision

Just as La Forge did, others accepted the VISOR as a normal part of the chief engineer's life, giving it no more thought than if he were wearing glasses or a hearing aid. This was demonstrated by the fact that La Forge enjoyed the senior officers' weekly game of poker on the Enterprise. Even though his VISOR allowed him to detect bluffing and see opponents cards in the ultraviolet spectrum, he always refused to 'peek' until a hand was over.

The fact that La Forge's crewmates accepted him into their games is evidence of the high regard they hold for their friend's integrity. However, there were times when the VISOR, which could alert La Forge to otherwise 'unseen' perils, became a dangerous burden.

The Romulans were able to use Geordi's neural implants to gain direct access to his visual cortex and provide filtered information that nearly caused La Forge to murder the Klingon governor Vagh in 2367. The plot was thwarted, but La Forge was left with a feeling of vulnerability he had not known before. La Forge was also forced to acknowledge the VISOR's shortcomings: the device proved unfortunately sensitive to quantum fluctuations.

On Stardate 42411.2, the U.S.S. Enterprise's chief medical officer, Katherine Pulaski, offered La Forge the possibility of replacing the VISOR with optical devices, which would more closely resemble 'normal' eyes while retaining the same range of vision. He was tempted, but decided against it. He eventually underwent surgery in 2371, receiving a set of ocular implants.