Scientists create contact lens that magnifies at blink of an eye
A contact lens that magnifies objects at the
wink of an eye has been created by
scientists to help people with impaired
vision.
The lens contains an extremely thin
telescope that is switched on when the
wearer winks their right eye and returns to
normal when they wink their left eye.
Eric Tremblay, a researcher at
Switzerland’s École Polytechnique
Fédérale de Lausanne (EPFL), said the lens
could help people with age-related
macular degeneration (AMD), which leaves
them with a blind spot in the centre of
their vision.
The contact lens magnifies objects by 2.8
times, making road signs, facial features
and other objects large enough for people
with AMD to recognise with their
peripheral vision.
The device was funded by Darpa, the
Pentagon’s research agency, as a means of
giving soldiers a form of bionic vision.
“They were really interested in
supervision, but the reality is more tame
than that,” said Tremblay at the American
Association for the Advancement of
Science. So far, only five people have
tested the latest version.
The device is larger and slightly thicker
than a normal contact lens. It allows the
wearer to see normally by correcting for
short or long sight. But around the central
region is a thin, ring-shaped reflective
telescope, which expands the perceived
size of objects like weak binoculars.
To swap between normal and magnified
vision, the wearer dons a pair of liquid
crystal glasses. By winking, they can switch
the glasses electronically to polarise light
in different planes. The contact lens is
designed so that one type of polarised light
goes through the normal, central part of
the lens, while the other goes through the
magnifying region.
More work is needed before the contact
lenses are ready for patients to wear
regularly. The latest lenses can only be
worn for about half an hour, because they
do not allow enough oxygen to pass
through them and into the eye. Tremblay
said he expected a working version of the
contact lenses to be available in two years
or so.
