UA Ophthalmologist's Research Could Lead to 'Super Vision'

George Humphrey
Feb. 16, 2001

Researchers at the University of Arizona are turning to optics technology used in telescopes to develop refractive surgery methods that could improve vision beyond the standard 20/20.

Jim Schwiegerling, Ph.D., a UA assistant professor with a joint appointment at the department of ophthalmology and the Optical Sciences Center, leads one of several groups around the country using light-measuring technology employed by telescopes to measure aberrations of the eye that limit vision acuity. These measurements would improve the efficiency of refractive laser surgery, resulting in much sharper vision.

When light travels through the atmosphere, it becomes distorted by atmospheric turbulence. Astronomers are able to correct the telescope image blurriness by using lasers and computers to measure the amount of distortion. The measurements are used to prompt a deformable mirror to quickly alter the incoming light wave front. This adjustment restores a sharp image of the object in the sky.

When light enters the eye through the pupil and travels through the orb to the retina, it is distorted by refractive error caused by natural aberrations on the cornea. These minute imperfections distort the light, causing blurry vision.

Utilizing the technology from telescopes, Schwiegerling is able to measure light reflected from the retina and use these measurements to plot a wave-front image that maps all the aberrations of the eye. Having this wave-front image could make it possible to customize refractive surgery to perfectly correct for all the aberrations. The outcome could be improved visual acuity beyond 20/20, as well in seeing low-contrast and dim objects. Schwiegerling said that it theoretically is possible to achieve acuity as fine as 20/5.

Schwiegerling's research will be critical as a second generation of excimer lasers - currently used in photorefractive keratotomy (PRK) and laser in situ keratomileusis (LASIK) surgeries - are being developed. Existing excimer lasers may correct most, but not all, of a patient's refractive error. Moreover, laser eye surgery creates new aberrations as a tradeoff for 20/20 eyesight.

"Our goal is to optimize the result of refractive surgery," Schwiegerling said. "Right now, the surgery allows people to see as well without their glasses as they do with. We want people seeing better than 20/20 after surgery."




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