Michael Bisping is done fighting. The former UFC middleweight champion made his announcement on Monday afternoon citing an eye issue that has been persistent since losing to Kelvin Gastelum in November 2017.

"So obviously I've teased this for a long time now: I might fight again, I might not. And unfortunately, it's not a fight that I'm announcing. I am going to announce my official retirement from mixed martial arts," Bisping said on his podcast "Believe You Me."

Bisping teased the idea of taking one more fight for his legacy for the last few months, but the issue with his eye has just become too much to handle.

"I realized there's no flash going on; it's just my eye, and every time I look left, it flashes. And it still does it now when it's dark," Bisping said. "It's light now, so I can't see it. So I started freaking out, thinking, 'Oh my God, I don't believe this, I've got a detached retina in my good eye.' I have problems with my bad eye; it doesn't look good, so obviously I was kind of freaking out."

The 39-year-old reached the pinnacle of the sport late in his UFC career when he captured the 185-pound title with a shocking TKO win over Luke Rockhold -- a fight he took on just 12 days notice. Bisping then defended the championship in a rematch from seven years earlier when he earned a decision over Dan Henderson in front of his home fans in Manchester, England. 

Bisping lost his title in the main event of UFC 217 when Georges St-Pierre came out of a four-year retirement to submit him in the third round. He then took the fight with Gastelum just 22 days after the brutal loss and was knocked out in the first round.

"I was watching this movie last night, and I just thought, 'It ain't worth it,'" Bisping said. "It ain't worth it. I mean, what else am I going to do? I've won the belt. I've had tons of wins. I've done everything that I set out to achieve. What's the point in flogging a dead horse? Not that I'm a dead horse, but what's the point? I've done everything that I set out to achieve, and fortunately, now I've used my platform to open other doors.

"You know, you've got to know when to walk away. I'm almost 40 years old. The time is now. So, I want to say, first of all, thank you to my wife. Without her, it wouldn't have happened. That's a fact. She was incredible every single step of the way. My children, my dad -- my dad was amazing. And of course, everyone in the U.K. and around the world that supported me."

Bisping (30-9) caps a career that spanned over 13 years. The Ultimate Fighter 3 winner currently holds the record for most fights in UFC history (29) and is tied with St-Pierre and Donald Cerrone for most wins in UFC history (20).