An assault trial over a fight that cost a man his left eye ended in a mistrial Wednesday when his prosthetic eye popped out as he was testifying, startling jurors.

John Huttick was weeping on the witness stand as he testified about the impact of losing his eye in the August 2011 fight in the parking lot of a bar called the New Princeton Tavern, The Philadelphia Inquirer reported.

Suddenly, the $3,000 prosthetic blue eye popped out. Huttick caught it and cried out as two jurors gasped and started to rise.

"I couldn't believe it just came out," Huttick said.

Judge Robert Coleman, who called it an "unfortunate, unforeseen incident," granted a mistrial motion by defense attorney Eileen Hurley. He scheduled a new trial for March 4.

A group of people including Huttick and defendant Matthew Brunelli had been drinking at the bar, Assistant District Attorney Mark Gilson said. Brunelli left with a girlfriend but got into an argument with another patron that turned into a fight in the parking lot, and when Huttick tried to separate the pair Brunelli threw a punch that hit Huttick's left eye, Gilson said.

Hurley said her client, who's charged with aggravated assault, struck Huttick with a fist, but Gilson said he "stabbed" Huttick with a metal key sticking out between his fingers.

Huttick, who's suing Brunelli, said that he lost his job because of the injury and that depression drained his finances and nearly broke up his relationship with his girlfriend.

"A year later," Huttick said, "I have no place to live, and I ran out of money."