Daniel Cormier was forced to fight with one working eye for two full rounds as he lost his bid to regain the UFC heavyweight title.
The 41-year-old suffered an eye poke at the end of the third round of his trilogy clash with Stipe Miocic in Las Vegas on Saturday night, Mirror UK reports.
UFC ref Marc Goddard missed the offence and told Cormier to fight on - although he later acknowledged his mistake.
And Cormier, after losing a unanimous decision in his final fight, was later taken to hospital after admitting he couldn't see from the affected eye.
"I can't see," he said. "He did a good job; he was able to clinch and hold me against the Octagon for long periods of time and I believe that separated the close rounds.
"I can't see anything out of my left eye, it's black but it is what it is. I told Marc but he said he thought it was a punch but after he said he'd seen it on the replay.
"I just can't see out of my left eye, it is what it is.
"It sucks, being on the losing end of two fights in trilogies is a very sad position to be in but I will deal with it as I've dealt with it in the past.
"I'm not interested in fighting for anything other than titles and I don't imagine there's going to be a title in the future so that will be it for me; I've had a long run and it's been great.
"I fought my last fight for the heavyweight championship and it was a pretty good fight."
After five closely-fought rounds, Miocic was given the nod by all three judges.
