When corneal epithelial stem cells are destroyed by severe trauma such as burn or autoimmune diseases, poor regeneration of corneal epithelium, persistent inflammatory reaction, neovascular ingrowth, and conjunctivalization may ensue, and seriously reduce the vision. In treating the diseased eye, when the other eye is healthy, limbal tissue containing corneal epithelial stem cells can be harvested for direct tissue transplantation, or ex vivo cultivation and expansion for several days before transplantation.