His is a gaze that can cut to the quick—a narrowing of the eyes that speaks a thousand words. Knowing the power of Clint Eastwood’s disdainful stare, Sergio Leone repeatedly fills the vast widescreen real estate of The Good, the Bad and the Ugly (1966) with nothing but his star’s eyes. Pity the fool on the receiving end: Clint’s glare is a prelude to action,...