Eye doctors could soon get a better look at your retina thanks to a technique used by astronomers to peer into the far corners of the galaxy. Using principles similar to those behind the Hubble Space Telescope, researchers from the University of California, Berkeley, and the University of Rochester have built a device that hooks up to standard eye-imaging equipment and improves resolution by a factor of three to five. That could allow doctors to image blood cells and photoreceptors in the eye-not possible in today's exam rooms-and detect diseases like glaucoma at an earlier stage. The device uses a six-millimeter-wide array of tiny movable mirrors to focus incoming light and correct for imperfections in the eye, such as a misshapen cornea. A built-in computer does the optical calculations and instructs the array to deform hundreds of times per second. In 2002, the researchers founded Iris AO in Berkeley, CA, to commercialize the technology. A federally approved device should reach doctors in three to five years.