Sir Michael Caine has admitted he spent eight years trying not to blink to perfect his acting technique.The legendary actor, 88, explained that a book titled Teach Yourself Film Acting featured the tip to “never blink” – leading him to spend eight years trying not to close his eyelids.Speaking to The Mirror, Caine said: “One thing that stuck in my mind was, ‘Don’t blink. You must never blink’.“For the next eight years, I walked around trying not to blink.