Clever reason Simon Cowell wears red-tinted glasses on BGT as they often get mistaken as fashion choice

Britain's Got Talent returned to our screens late last month for its 18th series, with the popular ITV show once again aiming to find the country's most talented performer.

Either that, or the one with the best sob story.

The show has introduced us to personalities such as Susan Boyle, Paul Potts and Diversity over the years, with beloved hosts Ant and Dec joined by judges Simon Cowell, Amanda Holden, Alesha Dixon, Bruno Tonioli and KSI.

This year's series kicked off in February and has already led to plenty of talking points, such as Simon being 'almost killed' by a sledgehammer in one of the show's most dangerous ever acts.

A performer's 'vile' act also managed to sneak onto the show, which is shown at 7pm, well before the 9pm watershed in the UK.

But it's arguably away from the acts where some viewers have been left most stumped, due to Simon's accessories.

The TV personality has been a mainstay on the show since its inception in 2007 and also a huge part of fellow musical talent show The X Factor. Somehow, perhaps using a mysterious anti-ageing injection, Simon has barely aged a day in the past 18 years on our televisions, something he has even joked about on the show.

However, he has been seen donning a pair of interesting red glasses in recent years, which have led to some fans speculating about his health.

But the 65-year-old assured followers that there is no need to worry, and clarified exactly why he wears the red-tinted spectacles in a social media post last year after he was forced to miss a couple of auditions during filming.

He wrote: "I just found out according to the internet, I have a 'mystery illness'. For anyone concerned, I missed two auditions at the end of one day, two weeks ago, because I do get migraines after long days in the filming lights. PS. This is why I wear these glasses!"

Given some of the interesting acts and singing voices we've seen on BGT over the years, it might not just be the filming lights that are contributing towards Simon's migraine, although he has already used his golden buzzer on this year's show, after being won over by the powerful voice of Vinnie McKee.

Britain's Got Talent airs on ITV and ITVX every Saturday evening at 7pm and is expected to run for another two months.