Peter Churm – blind in one eye and hard of hearing after a stroke – was attacked by Tommy Smith, a 17-year-old who believed he was possessed by a demon, Wolverhampton Crown Court heard.
He was armed with an eight inch kitchen knife and intended to steal the Range Rover belonging to the victim's son, said Mr Malcolm Morse, prosecuting.
Mr Churm was in the garage of his Owen Street, Dudley home when Smith – living in a flat in neighbouring Grove Street at the time and now aged 18 - struck on February 24 last year.
The victim recalled: "He started waving the knife about like a Kung Fu sword and I thought 'I'm in trouble here.'"
Smith launched the onslaught on the pavement outside the detached house and it continued along the drive, up three steps and into the porch, the court was told.
Mr Churm suffered 10 stab wounds – one narrowly missing the carotid artery – and other superficial injuries that needed 50 stitches and emergency surgery.
One ear was split in two while the other had the lobe almost completely amputated. He was also stabbed in the chest, side, head, neck and forearm.
Mr Churm picked up a claw hammer in the porch as Smith followed him.
Mr Churm said while giving evidence from behind a screen: "I was flapping about with the hammer. I knew that if I went down I was probably dead.
"I got two thumbs into his eyes and pressed. I don't know if I blacked out because I can't remember letting go of the attacker's eyes."
His 40-year-old data manager son Paul said: "I only saw him for a split second before he ran."
It is accepted that paranoid schizophrenic Smith was the knifeman but the jury must decide if he knew what he was doing when the stabbing took place.
The defendant, of no fixed address, is accused of attempted murder, causing grievous bodily harm and burglary. He denies the charges and the case continues.