After a lot of theorizing,
postulating, and non-human trials, it looks like bionic eye implants are
finally hitting the market — first in Europe, and hopefully soon in the
US. These implants can restore sight to completely blind patients —
though only if the blindness is caused by a faulty retina, as in macular
degeneration (which millions of old people suffer from), diabetic
retinopathy, or other degenerative eye diseases.
The first of these implants, Argus II developed by Second Sight,
is already available in Europe. For around $115,000, you get a 4-hour
operation to install an antenna behind your eye, and a special pair of
camera-equipped glasses that send signals to the antenna. The antenna is
wired into your retina with around 60 electrodes, creating the
equivalent of a 60-pixel display for your brain to interpret. The first
users of the Argus II bionic eye report that they can see rough shapes
and track the movement of objects, and slowly read large writing.
The
second bionic eye implant, the Bio-Retina developed by Nano Retina, is a
whole lot more exciting. The Bio-Retina costs less — around the $60,000
mark — and instead of an external camera, the vision-restoring sensor
is actually placed inside the eye, on top of the retina. The operation
only takes 30 minutes and can be performed under local anesthetic.
Basically, with macular
degeneration and diabetic retinopathy, the light-sensitive rods and
cones in your retina stop working. The Bio-Retina plops a
24×24-resolution (576-pixel!) sensor right on top of your damaged
retina, and 576 electrodes on the back of the sensor implant themselves
into the optic nerve. An embedded image processor converts the data from
each of the pixels into electrical pulses that are coded in such a way
that the brain can perceive different levels of grayscale.
The
best bit, though, is how the the sensor is powered. The Bio-Retina
system comes with a standard pair of corrective lenses that are modified
so that they can fire a near-infrared laser beam through your iris to
the sensor at the back of your eye. On the sensor there is a
photovoltaic cell that produces up to three milliwatts — not a lot, but
more than enough. The infrared laser is invisible and harmless. To see
the Bio-Retina system in action, watch the demo video embedded below.
Human
trials of Bio-Retina are slated to begin in 2013 — but like Second
Sight, US approval could be a long time coming. It’s easy enough to hop
on a plane and visit one of the European clinics offering bionic eye
implants, though. Moving forward, multiple research groups are working
on bionic eyes with even more electrodes, and thus higher resolution,
but there doesn’t seem to be any progress on sensors or encoder chips
that can create a color image. A lot of work is being done on understanding how the retina, optic nerve, and brain process and perceive images — so who knows what the future might hold.