The results, obtained by a University of Rochester team using a technology called adaptive optics that was originally developed by the military, are in the Feb. 11 issue of Nature . We're hopeful that someday the same technology that allowed us to do this work will help physicians more effectively diagnose and treat diseases that cause blindness. The findings were possible thanks to a laser-based system developed by David Williams and colleagues at the University over the last decade that maps out the topography of the inner eye in exquisite detail. The team built on technology known as adaptive optics, initially proposed by astronomer H.W. Babcock in 1953, then developed by the U.S. military to clear up images from spy satellites. The idea is to correct for aberrations in the atmosphere so that rays of light travel in parallel lines and converge at a single point, delivering a sharp image.
Astronomers use the technique in telescopes to grab ever-better photos of the heavens.
Williams, director of the University's Center for Visual Science, leads an effort to apply the same technology to human vision. Roorda and Williams took unprecedented photographs of the retinas of three people, two with normal color vision and one with color vision problems. The retina is basically a screen inside the eyeball that is packed with millions of cells known as cones and rods that detect light signals and convert them into electrical signals that the brain puts together to form images. Most cones detect either green or red light, and their arrangement has been completely unknown until now. One had about the same number of cones to detect green and red, while the other had four times as many cones to detect red light.