Apparently they've been using this technique to regrow irises in patients with chemical accidents since 2000, but the new twist is that they are now using it for aniridia.
"Aniridia results in near blindness since the limbal cells that keep the surface of the cornea clear and healthy are missing or few in number. Mr Daya takes a donor's limbal cells then grows them on in a laboratory. A sheet of the cells is placed over the patient's cornea, held by an amniotic membrane from donated placentas. After two or three weeks, the membrane dissolves but the stem cells remain and restore the epithelium, or top layer of the cornea. The donor stem cells themselves disappear over a few months, so immuno-suppressant drugs can be stopped."
Makes me think of the eyeball scene in Blade Runner.