Liu Bocheng was a marshal of the People's Liberation Army, a close friend of Deng Xiaoping. During his youth he was shot through the right eye. His eye was operated on by a German surgeon about whom I cannot discover much information but it seems that his name was Walker. Legend has it that Liu refused an anesthetic and after the operation he told the surgeon he had made 72 cuts. The surgeon was very impressed with Liu's stoicism and gave him the nickname "Chinese Mars" (军神).
This scene was filmed in an old complex of buildings based around a church on a mountaintop near Chongqing, probably quite close to where the event actually happened. The frightful looking wound is made of honey and red food colouring.