Retinal Microchip Puts Images Directly Into Brain

Blindness is the most debilitating of sensory impairments,
and also the most vexing to cure. Now, MIT scientists have
created a new kind of retinal implant that might help reverse
the effects of two common forms of blindness. Drawing on the
same principles as the cochlear implants that help the deaf,
this implant wouldn't restore vision, but could help the
blind navigate through everyday situations.

The system involves both a computer chip implanted on the
retina itself and a special pair of glasses that photographs
the surroundings and powers the implant. When the camera
records a large object like a wall or another person, it
sends a signal to the chip, which then electrically
stimulates nerves in the retina. The stimulated nerves send
an image to the brain that resembles dark splotches. The
number and size of the splotches indicate the size and
proximity of an object.

While the implant does not create a picture the wearer would
recognize as a particular object, the wearer can learn to
interpret the blobs in such a way that he or she could
navigate a space without danger of injury.

The implant prototype is the result of nearly 20 years of
work in the field, starting with the earliest tests that
proved electrodes could bypass a damaged retina, connect
directly to the optic nerve and produce an image in the brain
of a blind person. So far, the device has only been tested in
pigs, not humans, but MIT scientists hope to start human
testing within the next three years.