A five-minute vision test using a laptop computer with a
touch-sensitive screen can be used on Earth and in space to
help diagnose the onset of eye diseases and even certain types
of brain tumors.

With one eye covered, a person sits in front of a
computer screen divided into a grid. The subject stares at a
central spot on the touch-sensitive screen and, using a
finger, outlines missing areas of the grid. The computer
records, processes and displays a 3-D image of the subject’s
visual field. The test for each eye takes about 4 to 5

“As NASA moves forward to establish a permanent presence
in space, this may be
considered a breakthrough step for the creation of an
autonomous onboard physician,” said Dr. Wolfgang Fink,
physicist and senior member of the technical staff at NASA’s
Jet Propulsion Laboratory, Pasadena, Calif. “It is a non-
invasive, quick and easy process that gives astronauts and
physicians on the ground an almost instant auto diagnosis.
This type of technology will be useful for long-term space
missions where early detection and advance monitoring will be
key to the health of the astronauts.”

Fink, a visiting research assistant professor of
ophthalmology at the University of Southern California, Los
Angeles, developed the 3-D Computer-Based Threshold Amsler
Grid Test as part of his post-doctoral research while at the
California Institute of Technology in Pasadena, with his
colleague Dr. Alfredo Sadun, Thornton professor of
ophthalmology at USC. Caltech manages JPL for NASA.

“This new test is not only more revealing than standard
visual field tests, but it is also much quicker and simpler
than existing methods. This test may make visiting an
ophthalmologist cost-effective, convenient and fast, giving the
doctor a tool to do a better job,” said Sadun.

This tool has been undergoing testing in clinical trials
that began last year at the Doheny Eye Institute, Keck School
of Medicine at USC. Trial results show that the screening
test helps detect a variety of eye conditions, such as
glaucoma and macular degeneration– the two leading causes of
blindness. Early detection of these conditions and
appropriate treatment are crucial in preventing further loss
of sight.

Caltech has filed a full patent on the screening test,
and several companies have expressed interest in licensing the
technology that may become commercially available as early as
next year. Future uses envisioned are: monitoring the effects
of intracranial pressure elevation in low-gravity environments
and evaluation of possible stroke onset and of acute and
chronic stroke conditions. Funding for this project was
through a grant from the National Science Foundation,
Arlington, Va. JPL is the lead U.S. center for robotic
exploration of the solar system.

More information is available at:

http://www-aig.jpl.nasa.gov/public/mls/home/wfink/3DVisualFieldTest.htm .