When "Star Trek: The Next Generation" thrust the love of everything "Star Trek" back into popular culture, the quirky Mr. Spock and crass Bones McCoy and others were supplanted by a new cast. One of the most popular characters on the new show was engineer Geordi LaForge.
What made Geordi unique, perhaps even mysterious, was his funky eyewear. Geordi was blind, but after a surgical operation and aided through the use of a device called VISOR (Visual Instrument and Sensory Organ Replacement), Geordi could see throughout the electromagnetic spectrum. Though it may sound far-fetched, in reality, similar technology exists that may someday bring sight back to the blind.
In 2005, a team of scientists from Stanford University successfully implanted a small chip behind the retina of blind rats that enabled them to pass a vision recognition test. The science behind the implants, or bionic eyes as they're commonly referred to, works much the way Geordi's VISOR did. The patient receives the implants behind the retina, then wears a pair of glasses fitted with a video camera. Light enters the camera and is processed through a small wireless computer, which then broadcasts it as infrared LED images on the inside of the glasses. Those images are reflected back into the retina chips to stimulate photodiodes. The photodiodes replicate the lost retinal cells then change light into electrical signals which in turn send nerve pulses to the brain.
What it all means is that in theory, a person with 20/400 sight (blind), due to the loss of retinal cells from retinitis pigmentosa, can obtain 20/80 sight. It's not good enough to pass the driving test (normal vision is considered 20/20) but it's good enough to read billboards and go about your day without the aid of a seeing-eye dog.