Zac Efron thinks he has a huge head.

The 'Charlie St. Cloud' actor - who is in a relationship with actress Vanessa Hudgens - hates watching himself on screen and can't help but study his imperfections.

He said: "What do I think when I watch myself on screen? 'My head is huge!' I pick out every single flaw or thing I should have done better.

"I cringe at first, but years down the road I'll be able to look back and appreciate what I've done - sometimes."

The 22-year-old star also admitted he finds filming kissing scenes fun and likes to put girls at their ease.

He told Top Of The Pops magazine: "In my experience, I think girls get a little more nervous than I do. I like to be comforting if at all possible. Kissing is not a hard thing to do. I usually have a very cute girl opposite, so it's fun."

Zac loves making movies and is hopeful his work has a good effect on his fans.

He said: "I like to think movies have the ability to help people. If not, then why are we making them?"