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) several DC characters continuously published throughout the 1950s, there isn't a clear dividing line between the Earth-One and Earth-Two versions of Superman. Several stories published before the mid-1950s took place on Earth-One, such as "Superman" (volume 1) #78 from September–October 1952, the first appearance of the adult Lana Lang in Superman comics. Also, any Superman stories published before the mid-1950s that featured or mentioned Superboy also took place exclusively on Earth-One, as the Earth-Two Superman, per the earliest Superman comics, never had a Superboy career. The Earth-One Superman's first appearance in comics was in "Superman" (volume 1) #46 (May 1947),