The former UFC middleweight champ, 40, suffered a detached retina in his bout against Vitor Belfort in Brazil back in 2013, but battled on for a further 11 fights in his career.

That included defeating the legendary Anderson Silva in 2015 and picking up middleweight gold against Luke Rockhold the following year – then defending the title on home soil against Dan Henderson.

WATCH: Ex-UFC champ Bisping makes hasty exit after jokingly hitting combo on giant Kazakhstani stuntman

While Bisping lost the final two outings of his 39-fight career – against Georges St. Pierre and Kelvin Gastelum – it’s clear he has fighting with severe visual impairment.

The extent of that was plain to see when he popped out a prosthetic right eye live on his podcast ‘Believe You Me’.

“I wore my dark glasses to hide from the commission. That's why I used to wear f***ing sunglasses, baby boy!” Bisping said as he took out the eye – to the horror of co-host Luis J. Gomez.

WARNING: GRAPHIC VIDEO

It’s not reported when exactly Bisping had the fake eye fitted, although he told MMA journalist Simon Head earlier this year about the difficulties the injury from the Belfort bout had posed.   

“My vision was pretty much non-existent since 2013. I was just about able to scrape past the medicals. It was definitely touch and go…

“To pass the medical test, you’ve got to have 20-200 vision, which is classed as clinically blind anyway, so it’s not very good – it’s not a very hard mark to pass.

"Some days I could, some days I couldn’t. But fortunately, I was just able to scrape by,” the UFC Hall of Famer said back then.

“People always say: ‘How did you fight with only one eye?’ And I always say: ‘With great (expletive) difficulty!'”

The eye-popping revelation has caused MMA fans to recoil in horror but also express their admiration for a man already deemed a legend of the sport.

“Wow, I literally had no eyedea,” joked one Twitter user.