Mouth Cells Coaxed to Repair Eye Damage By Ed Edelson, HealthDay Reporter    HealthDayNews -- Japanese researchers say they have turned cells from the mouth into eye cells that have successfully been implanted in four patients to repair damage to the delicate outer layer of the cornea.    American ophthalmologists described the work as an impressive achievement in basic science, but one that needs much more investigation before it can be applied to treatment of patients when the outermost layer of the cornea is damaged by corrosive chemicals, fire or medical disorders...