Seeing, it’s
one of our five senses, and it is kind of important for getting
around. Almost all animals have some kind of ability to see,
with hawks and eagles having the best vision and rats having
some of the worse. And then there are bats which can hardly
see at all.
Scientists have
been studying the way the retina works. The retina is the part
inside of your eye that responds to light and helps to collect
images that allow you to see. The retina is made up of cells
called cones and rods that are special since they respond to
light. The average human eye has about a million cells and within
those cells about 150 million photoreceptors. Nerve cells then
connect these photoreceptors to your brain. But not every photoreceptor
is wired into your brain, so in your eye there is some information
processing going on. There is a lot of information that moves
from your eyes into your brain and scientists have estimated
it to be around 8.75 megabits per second, that’s around
5-10 times faster than a T-1 fiber optic cable.
If we know more about how the eye works then maybe someday
we can build artificial parts that might help people with visual
impairments to see better. Can nanotechnology help create artificial
eyes? Scientists have made some progress using technology that
is similar to the kinds of chips that are found in digital cameras.
The big challenge is not capturing the image since nanotechnology
can be used to make very small artificial retinas that are only
a few millimeters across. No, the real challenge is taking that
information collected on the artificial retina chip and somehow
directing that information to the brain. Clinical trials have
already been started with the artificial retina mounted on a
pair of glasses and then the electrodes then wired into the
retina of the patient. What do the patients see? Not real images
but bits and pieces that mainly correspond to light and dark.
Part of the challenge for the patient is retraining the brain
to understand this information. There is still a lot of work
to be done, but things are moving along!
Image Sources: Wikipedia
| Telegraph