Prince William lost his public speaking nerves thanks to his deteriorating eyesight.

The 37-year-old future king admitted he used to experience a ''bit of anxiety'' ahead of having to address a crowded room, but when he was unable to distinguish faces because of his poor vision, he felt more confident as he didn't feel under so much scrutiny.

He said: ''You're like, 'This has to go right. I don't want to mess this up'. There's a lot of people watching and you can see certain people.

''My eyesight started to sort of tail off a little bit as I got older, and I didn't used to wear contacts when I was working, so actually when I gave speeches I couldn't see anyone's face.

''It helps because it's just a bit of a blur of faces, and because you can't see anyone looking at you. I could see enough to read the paper and stuff like that, but I couldn't actually see the whole room.

''And actually that really helped with my anxiety.

''I didn't realise at the time but looking back I'm like that's what helped because I couldn't see everyone's eyes, you don't feel like the whole weight of the room is watching you.''

Elsewhere in documentary 'Football, Prince William and our Mental Health', the royal - who has Prince George, six, Princess Charlotte, five, and Prince Louis, two, with his wife, the Duchess of Cambridge - admitted becoming a father brought back the trauma of losing his mother, Princess Diana, in a car crash in 1997.

Speaking to Marvin Sordell, who quit football last year due to depression, he opened up after the former Watford striker admitted becoming a dad in 2017 brought back painful memories of growing up without his father.

William said: ''Having children is the biggest life-changing moment, it really is.

''I think when you've been through something traumatic in life and that is, like you say, your dad not being around, my mother dying when I was younger, the emotions come back in leaps and bounds.

''Because it's a very different phase in life and there is no one really there to help you. I definitely found it at times very overwhelming.''

'Football, Prince William and our Mental Health' airs on BBC One on Thursday (28.05.20) evening.