Russell Turnbull, now 38, lost almost all the sight in his right eye after trying to break up a fight and being sprayed with ammonia 15 years ago. The result for him was what's known as Limbal Stem Cell Deficiency, which caused him great pain, the need for therapeutic treatment, and economic dependency. Good news for Russell is that he can put all that behind him now, after becoming one of the first recipients of a new stem cell grafting procedure, whereby healthy tissue from his left eye was implanted into his right and -- just like a video game medpack -- restored his vision to normal. For the moment, this treatment is limited to patients with at least one healthy eye, but given the pluripotent nature of stem cells, it is hoped that tissue from elsewhere in the body could one day be used to regenerate damaged parts , such as the cornea in this case. You may find further enlightenment in the video after the break.