(Cover) - EN Showbiz - Matt Damon blames his greying hair on his four daughters.

The American actor has recently turned 40 and noticed tufts of lighter hair among his brown locks.

But rather than credit the traditional sign of ageing to his busy Hollywood career, Matt says his children - four-year-old Isabella, two-year-old Gia, Stella, who was born in October, and Alexia, Lucianas daughter from a previous relationship - are responsible for his stressed state and declining youthful looks.

"The grey hair I definitely attribute to my kids. I always say to them this [grey hair] is all you and this side here is you!" He told British newspaper The Independent.

The actors life has changed irreversibly since meeting his wife Luciana, then a barmaid, eight years ago.

Matt didnt used to believe in love at first sight, but as soon as he laid eyes on his brunette wife, there was no going back.

"People say that thing about seeing someone across a crowded room. I swear to God that happened to me. Not to get too hokey, but it did, definitely. I was shocked. It was something very weird, he said. "I moved and suddenly she wasn't just my wife. It was also a four-year-old little girl who's now twelve. There was never a choice. It was just the way it was and I was happy for that. I can't imagine my life having not gone down that road, or what my life would be now otherwise. I don't want to imagine it. (C) Cover Media