Back in the late 80's I had my ex-girlfriend shoot my Ruger Mk. 2 and a piece of the brass casing came off and hit her in the eye when the gun was ejecting the fired round, she was not wearing any safety glasses. She was really hollering, the spent cases are very hot to begin with, and having that hit a person's eyeball is not good. I found and kept that spent case for many years with my cartridge collection.
She did not have any eye damage that I could see. I always wear eye protection.