A possible cure for corneal blindness using adult stem cells rather than those from embryos is to undergo trials in Edinburgh and Glasgow.
The move follows dramatic improvements in vision that occurred after a corrective gene was injected into the eyes of subjects in earlier trials at the University of Pennsylvania.
While embryo stem cells can differentiate into a diverse range of specialised cell types, adult cells act as the body's repair and replenishment system.
The corneal technique uses stem cells from dead adult donors that are cultivated before being transplanted onto the surface of the cornea.
Professor Bal Dhillon at the Princess Alexandra Eye Pavilion in Edinburgh is heading the trial, in collaboration with the Gartnavel General Hospital in Glasgow.
He said: "This study is the first of its kind anywhere in the world and it is exciting to be involved in such groundbreaking work. I probably see two or three new cases of corneal disease every month. On a larger scale, it's a significant problem."