Michel Fourgere told court today he was caught completely off guard when he was grabbed by fellow inmate Mark Lindsay at the Kamloops Regional Correctional Centre last year.
Court heard Fourgere lost sight in one of his eyes in the attack.
Fourgere was visibly emotional and wore dark glasses during his testimony and declined comment to reporters after his court appearance.
Lindsay admitted to the Scrabble attack in court last week, and also admitted to slashing an undercover police officer and to killing his former girlfriend.
On Thursday, Lindsay's lawyer, Don Campbell, said the judge ordered the psychiatric assessment to help determine if Lindsay is not criminally responsible for his actions because of a mental disorder.
The 30-day psychiatric assessment will be conducted in Vancouver
Lindsay told court he killed Turner in a panic before dumping her body, which was found last October in a field near Innisfail, Alta. He said he believed she was a serial killer and his life was in danger.
He also testified a group of serial killers was after him over false allegations that he sexually assaulted one of their friends and they spoke to him in person, on his cell phone and by psychic means.
Lindsay is the son of a former Edmonton police chief.
Last weekend, John Lindsay and his wife issued a statement saying they are "very greatly saddened by the profound pain of all who have suffered'' from the events described in court.
The couple said health problems have prevented them from attending their son's court proceedings, but that they love their son.