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Abstract
For those millions of us whose vision isn’t perfect, there are
glasses. But for those hundreds of thousands who are blind,
devices that merely assist the eyes just aren’t enough. What they
need are alternative routes by which the sights of the world can
enter the brain and be interpreted. Technology has created many
path ways for the mankind. Now technology has improved to that
extent wherein the entire human body can be controlled using
a single electronic chip. We have seen prosthetics that helped
to overcome handicaps. Bio medical engineers play a vital role
in shaping the course of these prosthetics. Now it is the turn of
artificial vision through bionic eyes. Chips designed specially to
imitate the characteristics of the damaged retina and the cones
and rods of the organ of sight are implanted with a microsurgery.
Linking electronics and biotechnology, the scientists have made the
commitment to the development of technology that will provide or
restore vision for the visually impaired around the world. Whether
it is Bio medical, Computer, Electrical, or Mechanical Engineers
all of them have a role to play in the personification of Bionic
Eyes. There is hope for the blind in the form of bionic eyes. This
technology can add life to their vision less eyes.
Introduction
Belonging to the community of engineers there is no frontier
that we cannot conquer. If scientists give birth to ideas, then it
is we engineers who put life into those ideas. Today, we talk of
artificial intelligence that has created waves of interest in the field
of robotics. When this has been possible, then there is a possibility
for artificial vision. `Bionic eye’ also called a Bio Electronic eye,
is the electronic device that replaces functionality of a part or
whole of the eye. It is still at a very early stage in its development,
but if successful, it could restore vision to people who have lost
sight during their lifetime. This technology can add life to their
visionless eyes [1].
A bionic eye works by stimulating nerves, which are activated
by electrical impulses. In this case the patient has a small device
implanted into the body that can receive radio signals and transmit
those signals to brain through nerves and can interpret the image.
One of the most dramatic applications of bionics is the creation
of artificial eyes. Early efforts used silicon-based photo detectors,
but silicon is toxic to the human body and reacts unfavorably with
fluids in the eye. Now, scientists at the Space Vacuum Epitaxy
Centre (SVEC) based at the University of Houston, Texas, are
using a new material they have developed, tiny ceramic photocells
that could detect incoming light and so repair malfunctioning
human eyes We are able to see because light from an object can move through
space and reach our eyes. Once light reaches our eyes, signals are
sent to our brain, and our brain deciphers the information in order
to detect the appearance, location and movement of the objects
we are sighting at. The internal working of eye is as follows [3],
Scattered light from the object enters through the cornea.
1. The light is projected onto the retina.
2. The retina sends messages to the brain through the optic
nerve.
3. The brain interprets what the object is.
The eyeball is set in a protective cone-shaped cavity in the skull
called the orbit or socket and measures approximately one inch
in diameter. The orbit is surrounded by layers of soft, fatty tissue
which protect the eye and enable it to turn easily. The important
part of an eye that is responsible for vision is retina. The retina
is complex in itself. This thin membrane at the back of the eye is
a vital part of your ability to see. Its main function is to receive
and transmit images to the brain. In humans there are three main
types of light sensitive cells in the retina. They are [3],
• Rod Cells
• Cone Cells
• Ganglion Cells
There are about 125 million rods and cones within the retina that
act as the eye’s photoreceptors. Rods are able to function in low