Bruno Coutinho was cleaning his harpoon gun at his Petropolis home when the gun accidentally fired, sending a harpoon through his left eye and into his head, Sky News reported Friday.
Coutinho was taken to Santa Teresa hospital, where an X-ray showed the metal harpoon went straight through to the back of his cranium.
Surgeons removed the harpoon in a pair of operations more than 10 hours after it became lodged in Coutinho's head.
Dr. Orlando Maria, chief of neurosurgery at the hospital, said the harpoon very nearly pierced a major artery.
"The object, it seems, took a path where it didn't damage any vital structures, any vascular structures and was taken out," Maria said.
He said Coutinho avoided brain damage, but lost his left eye. Coutinho is expected to be discharged from the hospital within a few days, Maria said.