Complex sentence: Various methods for keeping his Superman identity secret over the years include his using eyeglasses and "super-hypnosis", subliminally preventing people from making the connection, compressing his spine as Clark Kent to become shorter, and studying the Meisner acting technique to switch seamlessly between personas.
Split into simpler sentences: Various methods for keeping his Superman identity a secret over the years include wearing eyeglasses and "super-hypnosis", subliminally preventing people from making the connection. He also compresses his spine as Clark Kent to become shorter and studies the Meisner acting technique to switch seamlessly between personas.