They made a couple of music videos with a similar theme - how they looked when they first started and how the band looks now. This scene on the left is from "Wildest Dreams", which came out in 1986. 
Obviously Justin Hayward couldn't play himself as a teenager, so they approached a young and upcoming actor, just out of the London Academy of Music and Dramatic Art, who did look uncannily like a very young Justin.

Two years later, the group were making a similar video for "I Know You're Out There Somewhere", and the same actor was available again.
And he's been busy ever since.
Ben Daniels

Ben Daniels then appeared in a number of minor roles on shows such as "Drop the Dead Donkey" and "Capital City", before landing the role of Alex Harrington in "Outside Edge". Then there was the part of "Tony" in "Beautiful Thing", as seen above.

He can do the action roles. In the "Doom" movie, Ben played "Goat". And got to play with BFGs.

"The State Within", a US/UK political action thriller, had him playing a British diplomat having an affair with a US political aide, passing information backwards and forwards, and playing about a dozen other cards at the same time. It was also had some rather hot and steamy scenes where the two men were more than just "politically involved".

Ben plays "James Steel", a barrister in the series "Law and Order: UK", using cold hard legalities to uphold the law.
He's also very very active in theatre work, and was nominated for a Tony for his performance as Vicomte de Valmont in "Dangerous Liaisons" on Broadway in 2008.
And for the curious, (as I always am when someone is cast as a "younger version"), here's Justin Hayward at age 44, the same as Ben was when the picture was taken for "Law and Order:UK".
December 3 2010, 20:00:26 UTC 1 year ago
January 11 2011, 14:35:46 UTC 1 year ago
The Moody Blues + Ben Daniels = fantastic!!!
Hi! The Moody Blues made one of my favorite songs of the ‘60s, “Nights in White Satin”, what a surprise to find out they worked together with Ben Daniels in the ‘80s!I've dedicated a fan page to good actor Ben Daniels, me too I've posted some screen shots from those videos there.
January 11 2011, 15:05:39 UTC 1 year ago
Re: The Moody Blues + Ben Daniels = fantastic!!!
When researching my NaNoWriMo novel last year, someone suggested I "cast" the characters. I decided the main character should be played by Mr Daniels, and now the wretched character won't sound or behave like anyone else! Dammit! More seriously, saw him first in "The State Within", and I've now bought "Law and Order:UK" just to watch more of him.So glad you liked this!