One small piece at a time, scientists are developing the means to replace damaged portions of your body. Here, via the Daily Yomiuri, is another part of the eye, to go along with progress in regenerating retinal cells: "A team of researchers at Tokyo University Hospital has succeeded in using a cornea cell to grow cornea epithelial tissue, which is essential for treating deteriorating eyesight caused by damage to the surface of a cornea caused by the side effects of medicine or drugs. ... [the researchers] harvested limbal cornea from the peripheries of the pupils. The team then used an enzyme to turn the limbal cornea into pieces to cultivate it. The pieces grew into clumps with a diameter of 0.3 millimeters in about one week. Three weeks later, they became cornea epithelial tissue in sheets with a diameter of about two centimeters. The three-dimensional tissue is similar to ordinary cornea epithelial tissue. Yamagami said he planned to make a clinical application for it in several years."