Contact Lenses To Get Advanced-Now, contact lenses that allow you to zoom in and zoom out

GENEVA: Researchers have unveiled the latest
version of a first of its kind telescopic contact
lens that allows the wearer to zoom in and out
with the wink of an eye.
The contact lenses have to be paired with smart
glasses that recognize winks and ignore blinks
to allow wearers to switch between normal and
magnified vision.
"We think these lenses hold a lot of promise for
low vision and age-related macular
degeneration (AMD)," said Optics specialist Eric
Tremblay from Ecole Polytechnique Federale de
Lausanne in Switzerland.
There are glasses already on the market for
people with AMD that have mounted telescopes,
but they tend to look bulky and interfere with
social interaction.
They also do not track eye movement, so users
have to position their eyes and tilt their head
to use them. The first version of the telescopic
contact lens -- which magnifies 2.8 times --
was announced in 2013.
Since then scientists have been fine-tuning the
lens membranes and developing accessories to
make the eyewear smarter and more
comfortable for longer periods of time, and
thus more usable in every day life.
The lenses work by incorporating a very thin
reflective telescope inside a 1.55mm thick lens.
Small mirrors within bounce light around,
expanding the perceived size of objects and
magnifying the view, so it's like looking
through low magnification binoculars.
At this time, the telescopic contacts are made
using a rigid lens known as a scleral lens -
larger in diameter than the typical soft
contacts you might be used to and valuable for
special cases, such as for people with
irregularly shaped corneas, researchers said.
Although large and rigid, scleral lenses are safe
and comfortable for special applications, and
present an attractive platform for technologies
such as optics, sensors, and electronics like the
ones in the telescopic contact lens, researchers
said.
The final lenses are made from several precision
cut and carefully assembled pieces of plastics,
aluminum mirrors, and polarising thin films,
along with biologically safe glues.
Since the eye needs a steady supply of oxygen,
the researchers have spent the last couple of
years making the lenses more breathable - a
critical requirement.
To achieve oxygen permeability, they are
incorporating tiny air channels roughly 0.1mm
wide within the lens to allow oxygen to flow
around and underneath the complex and
normally impermeable optical structures to get
to the cornea.
The electronic glasses paired with lenses use a
small light source and light detector to
recognize winks and ignore blinks. The wearer
will wink their right eye for magnification, and
left eye for normal vision.
This switching functionality is crucial for the
lenses to be widely useful for non-AMD
sufferers who will be able to have
magnification "on demand."
The lens prototype was unveiled at a meeting of
the American Association for the Advancement
of Science (AAAS) in San Jose, California.