Scott Summers was the first of two sons born to Major Christopher Summers, a test pilot for the U.S. Air Force, and his wife Katherine. Christopher was flying his family home from vacation when their plane was attacked by a spacecraft from the interstellar Shi'ar Empire. To save their lives, Katherine pushed Scott and his brother Alex out of the plane with the only available parachute. Scott suffered a head injury upon landing, thus forever preventing him from controlling his mutant power by himself.
With their parents presumed dead, the authorities separated the two boys. Alex was adopted, but Scott remained comatose in a hospital for a year. On recovering, he was placed in an orphanage in Omaha, Nebraska that was secretly controlled by his future enemy, the evil geneticist Mister Sinister.
As a teenager, Scott came into the foster care of Jack Winters, a mutant criminal known as the Jack O'Diamonds. After Scott began to suffer from severe headaches he was sent to a specialist who discovered that lenses made of ruby quartz corrected the problem. Soon after, Scott's mutant power first erupted from his eyes as an uncontrollable blast of optic force. The blast demolished a crane, causing it to drop its payload toward a terrified crowd. Scott saved lives by obliterating the object with another blast, but the bystanders believed that he had tried to kill them and rallied into an angry mob. Scott fled, escaping on a freight train.
Winters sought to use Scott's newfound talent in his crimes, and physically abused the young boy when he initially refused. However, Scott's display of power had attracted the attention of the mutant telepath Professor Charles Xavier, who teamed up with F.B.I. agent Fred Duncan in their mutual attempt to find Scott. Scott was rescued from Winters' clutches and was enlisted by Xavier as the first member of the X-Men, a team of young mutants who trained to use their powers in the fight for human/mutant equality.
As Cyclops, Scott became deputy leader of the X-Men. While he was a skilled tactician, his social skills were lacking. Scott had fallen in love with his teammate Jean Grey, but his reserved demeanor prevented him from expressing his feelings for her for years. When Xavier's other original recruits left the fold following an encounter with the sentient island-being Krakoa, Cyclops stayed on as deputy leader of the new team.