INDIANAPOLIS -- Technology that astronomers developed to take the twinkle out of starlight as it enters their telescopes is now peering in the opposite direction, revealing the eye's complexities as never before. Scientists hope the detailed images of light-gathering cells they can now see will lead to early diagnoses and treatment of eye diseases to spare patients from blindness.
The same system of lenses, flexible mirrors and computers is also making laser eye surgery more accurate. One day it may even allow surgeons to userlasers to zap away tiny aneurisms within the eye.
"The real breakthrough is the work of these clever astronomers. All we've done is steal their ideas and try to put them to use for vision science," said Larry Thibos, a professor of optometry at Indiana University who is helping refine the technology for vision space.
Called adaptive optics, it was first proposed in 1953 by an astronomer eager to compensate for the distortions that light from stars, planets and galaxies picks up while passing through Earth's soupy atmosphere. But it was not until the 1980s that such technology was refined, as part of research on President Reagan's failed "Star Wars" program to build a missile defense shield of space-based lasers.
After that technology was declassified in 1991, it quickly found its way into the nation's biggest telescopes. Deformable mirrors that can be rapidly changed in shape to compensate for atmospheric turbulence soon began steadying starlight in major observatories.
The resulting images can be crisper than those captured by the Rubble I telescope, which orbits the Earth high above its atmosphere.
Adaptive optics' potential uses for vision science purposes was not lost
on the National Science Foundation, which began funding research studying its vision applications in the 1990s.
Just like Earth's atmosphere, the eye's cornea, lens, vitreous fluid and other structures prevent ophthalmologists from getting a clear view of the retina--the light-sensitive region at the back of the eye that converts images into nerve impulses sent on to the brain.
Scientists quickly adapted the telescopic technology into an instrument called an ocular aberrometer that measures imperfections in light reflected off the retina. That information is fed to a computer that calculates how a deformable mirror should be warped with tiny adjusters to correct for those distortions by rippling its surface with tiny pits and dimples.
Sort of like making a soda bottle's blurry bottom suddenly turn clear, the system is giving scientists their clearest views yet of the retina.
David R. Williams, a professor of a medical optics at the University of Rochester, said vision scientists are eager to use the technology to see the retina's ganglion cells, cells that encode and transmit visual information to the brain as nerve impulses. …