It was a century ago that Harold Lloyd first donned the pair of horn-rimmed glasses that would forever change the arc of his career. Featured in such slapstick classics as Safety Last! and Speedy, the glasses character gave Lloyd the chance to showcase his inventive approach to physical comedy and his impeccable timing, qualities that established him as one of the great clowns of silent cinema. Over on the Criterion Channel on FilmStruck, we’re celebrating the centennial of this iconic role with a spotlight on Kevin Brownlow and David Gill’s documentary Harold Lloyd: The Third Genius. With reminiscences from industry veterans—including writer-producer-director Andrew L. Stone, who was a cinema manager in the silent era—the excerpt below charts Lloyd’s transition from his earlier on-screen persona “Lonesome Luke” to the bespectacled alter-ego that made him a star. Watch the documentary now on the Channel along with five of the actor’s greatest performances.