http://www.sciencedaily.com/releases/2000/06/000612084400.htm
<http://www.sciencedaily.com/releases/2000/06/000612084400.htm>
Source: University Of Rochester ( http://www.rochester.edu/)
<http://www.rochester.edu/)>
Date: Posted 6/12/2000
Technology First Aimed At Heavens Now Makes "Super" Human Vision
Possible
Adapting technology originally developed by astronomers to obtain
better
images of the heavens, a University of Rochester scientist has
developed
an optical system that has given research subjects an unprecedented
quality of eyesight. The research dramatically improves the sight even
of
people who have 20/20 vision. Vision scientist David Williams
presented
his work this week at the summer meeting of the American Astronomical
Society in Rochester, N.Y.
While the work is still in a research stage, eye-care giant Bausch &
Lomb
has licensed the technology and is working with University researchers
to
commercialize it.
"For years David has been way out in front exploring how we could
enhance
people's vision beyond what is normally thought of as perfect vision,"
says Scott MacRae, one of the world's leading cornea specialists and a
widely recognized pioneer in refractive surgery. MacRae is moving to
the
University's Medical Center this month to join Williams at the newly
established Alliance for Vision Excellence, a new collaboration
between
the University and Bausch & Lomb that is dedicated to improving
technology
to correct vision-impairing anomalies of the eye.
"In the old days," says MacRae, "we were just trying to correct
people's
vision problems and treat disease. This new research takes what we
consider normal vision and enhances it. This is truly revolutionary,"
says
MacRae, who is writing a book on such research, which he calls "the
quest
for super vision." Just last month at the annual meeting of the
Association for Research in Vision and Ophthalmology, researchers from
several laboratories and companies devoted a whole symposium to the
topic
of enhanced vision.
Williams uses technology known as adaptive optics, which was
originally
developed by astronomers to sharpen images from telescopes by
correcting
for aberrations in the atmosphere. Adaptive optics have been
implemented
on several telescopes, including the giant Keck Telescope in Hawaii,
resulting in remarkably crisp images. Williams, who is Allyn Professor
of
Medical Optics and director of the University's Center for Visual
Science,
has led a decade-long effort to apply the technology to improve
ordinary
human vision.
His researchers direct a harmless, highly focused spot of light into
the
eye of a research subject and measure the light that is reflected
outward.
That light provides a glimpse or snapshot of the topography of the eye
in
exquisite detail. The light is broken up into 217 laser beams that are
sent into a sophisticated device known as a wavefront sensor. The
sensor
analyzes deviations in each beam's path, revealing tiny imperfections
or
aberrations that exist in the person's cornea and lens.
The system detects visual distortions so subtle that physicians didn't
even know they existed until Williams' laboratory invented the system.
Today a visit to the eye doctor focuses mainly on two types of
aberration:
astigmatism and defocus. Most prescriptions are intended to correct
for
these two defects. Williams' system can measure up to 65 different
aberrations.
These precise measurements are sent to a sensitive "deformable" mirror
--
a mirror that can bend and customize its shape according to the
measurements of a person's eye. Such flexible mirrors form the heart
of
traditional adaptive-optics systems used in astronomy. The mirror in
Williams' laboratory is a two-inch-wide device that bends as little as
one
or two micrometers (just one-fiftieth the width of a human hair)
thanks to
37 tiny computer-controlled pistons. This subtle shaping, done in
response
to the customized measurements of a person's optical system, alters
the
light in such a way that it exactly counters the specific distortions
in a
person's eye.
In the laboratory, Williams' team has shown that correcting these
imperfections can result in greatly improved vision. He has published
this
work in the Journal of the Optical Society of America.
"When you look through an adaptive optics device, the world looks
crisper," Williams says. "In some people, the ability to pick up
contrast,
such as minute patterns of stripes, is increased by a factor of six.
It
allows for a level of vision correction that's just not available
today.
"It's like needing glasses and getting them for the first time.
Everything
suddenly looks sharper and clearer, no matter how good your eyes are
normally. When you're using the adaptive optics system, you just say
'wow.' "
Williams is an expert on the circuitry of the human retina and the
optics
of the eye. After discovering some of the basic limits of the optical
system of the human eye, he began exploring ways to improve ordinary
human
vision, eventually working closely with astronomers and other
adaptive-optics experts. The research is now funded by the National
Science Foundation Center for Adaptive Optics (based at the University
of
California, Santa Cruz), the National Eye Institute, and Bausch &
Lomb.
Williams has found that the visual acuity of the human eye can be
somewhere around 20/10. While adaptive optics may someday help
patients
approach that level, he says that acuity isn't the most noticeable
improvement. Adaptive optics improves eyesight most under low-light
conditions, such as night-time driving. MacRae, the laser surgery
expert,
estimates that a driver sharing the road with a bicyclist at dusk
could
see the bicyclist from roughly twice as far away if he or she were
equipped with adaptive optics correction.
In the past, Williams has used the system to look into the eye. In a
series of papers in such journals as Nature, Williams' team has
published
the best images ever obtained of the living human retina. Last year
the
team was able to differentiate the three types of cones in the living
human retina. Detailed information of the eye is helpful to
ophthalmologists monitoring patients with diseases like age-related
macular degeneration or diabetic retinopathy.
While the current set-up is too bulky to bring the experience of
enhanced
vision or super vision to many patients, MacRae is confident that that
day
is not too far off.
"Someday you may no longer have to sit and answer patiently when
you're
asked repeatedly whether lens No. 1 or lens No. 2 is better," MacRae
says.
"Someday you may just look into a wavefront sensor as David has
developed,
and in one quick second we'll have all the information needed to
improve
someone's vision dramatically."
Editor's Note: The original news release can be found at
http://www.rochester.edu/pr/News/NewsReleases/latest/WilliamsAAS.html
<http://www.rochester.edu/pr/News/NewsReleases/latest/WilliamsAAS.html>
Note: This story has been adapted from a news release issued by
University
Of Rochester for journalists and other members of the public. If you
wish
to quote from any part of this story, please credit University Of
Rochester as the original source. You may also wish to include the
following link in any citation:
http://www.sciencedaily.com/releases/2000/06/000612084400.htm
<http://www.sciencedaily.com/releases/2000/06/000612084400.htm>
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