Superman (1939). Certain materials such as lead can block his X-ray vision. Superman can project beams of heat from his eyes which are hot enough to melt steel. He first used this power in "Superman" #59 (1949) by applying his X-ray vision at its highest intensity. In later stories, this ability is simply called "heat vision". Superman can hear sounds that are too faint for a human to hear, and at frequencies outside the human hearing range. This ability is introduced in "Action Comics" #11 (1939). "Action Comics" #1 (1938) explained that Superman's strength was common to all Kryptonians because they
Superman (Earth-One) the first time Superboy was referenced in a Superman story. The Earth-One Superman's first appearance (in a flash-forward) in a Superboy story was in "Superboy" (volume 1) #1 (March–April 1949). This version of Superman remained in publication through 1986. After the 1985-86 miniseries "Crisis on Infinite Earths", the Earth-One Superman was written out of continuity with the 1986 John Byrne miniseries "The Man of Steel". However, the Earth-One Superman was given a send-off in the final, noncanonical-to-Earth-One "imaginary" story "Whatever Happened to the Man of Tomorrow?" in "Superman" (volume 1) #423 (September 1986) and "Action Comics" #583 (September 1986). "For