Bionic Eye

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Restoring Sight:
International Research on
Bionic Eye
The notion of restoring sight to the blind has, until now, been restricted to the realms of miracles or parable. But for
the past ten years research scientists from Australia and the United States have been working on a “bionic” eye or visual
prosthesis that is beginning to accomplish the heroic quest of actually restoring sight to some people who are blind.
| Professor Gregg Suaning |
In Australia, a group of 20 graduate
students and researchers have
developed a bionic eye capable of
detecting not only light and dark but
also patterns. Professor Nigel Lovell,
from the University of New South
Wales’ Australian Vision Prosthesis
Group (AVPG) says a functional device
can be a reality within 12 years with a
concerted national effort.
Associate Professor Gregg Suaning,
also with the AVPG, said the current
device consists of an external
micro-camera and microprocessor
which is mounted on glasses and
transmits a signal to an implanted
electronic circuit and electrode,
connected to the retina at the back of
the eye.
How does it work? In certain
disease processes the sense organs
die or degenerate. In the case of where
bionic eyes could act as a device
therapy, the photoreceptors are
damaged. However the nerve cells that
connect the sense organs to the brain
are still intact and functional. As Lovell
explains: “Electrical current is passed
through these nerve cells to create
action potentials that, in a crude
manner, mimic the normal nerve traffic
VISION | jul_aug | 2008 | The Opticians Association of Canada |
By Paddy Kamen
that the brain would experience from
the sense organ. Obviously the form
that this nerve traffic takes is far from
the real case, so we rely heavily on
brain remodeling, or plasticity, to make
sense of the nerve signals.”
“Animal experimental data, mathematical
modelling and low-vision
psychophysics simulations in normally
sighted human volunteers show that
our approach of placing the electrode
in the suprachoroidal space (behind
the retina and in between the sclera
and choroid) is functional,” says
Lovell.
There are more than 100 million
photoreceptor cells in each eye.
Current devices, like the one designed
by the Australian team, are limited in
the number of electrodes they can
place on the retina. According to
Lovell, 100 electrodes would allow face
recognition and reading. To date his
device has tested with 14 electrodes.
There is a huge gap between what is
envisioned and what is currently
possible. However, Lovell’s group has
patented unique technology that
creates "virtual dots" around the
electrodes, making it easier to create a
better image with fewer electrodes.