I had no idea stem cells could be found in corneas. Apparently there's hope that other body parts will also be able to be regenerated from stem cells taken from healthy tissue in them. I assume that will only apply to simple parts, not things like entire arms or legs. It took many years for the cornea treatment to be completed so research about using the technique for other body parts will probably also take a while.
Obviously I have no expertise in this area and don't know what I'm talking about, but the discovery does sound hopeful. Here's one of many news stories about it: