Also why did he wear the specs before the tights?
Interesting question. I always thought it as a way to hide his strength. You don't beat on the wimpy guy with glasses. It gave him an excuse to avoid contact sports.
But I've not seen any evidence of that from his youth. Then again in the beginning the comics start with Superman up and going and his fosterparents dead.
I've always wondered if it's purely a creation of this fandom or something from the comics/movies/somewhere else that prompts most of us to use the idea of Clark wearing glasses (lead and all that) as a way to control his emerging powers as a teen?
It seems that way, in the beginning his glasses was made of krypton materials allowing him to use his heat-vision through them.
This page goes through the change of Superman over time in great detail, check the biology section
. In 1986 With a "man of steel" Superman got a large remake in order rekindle interest.
These are many of those changes we see in the series that aren't original:
The planet Krypton was a cold and emotionally sterile planet.
Although all of his standard superpowers remained, Superman was effectively limited in power and scope; while the pre-Crisis Superman at his peak could easily move planets, the post-Crisis version strained at moving a commercial airliner in flight.
While the pre-Crisis Superman's costume was invulnerable (as a result of being made from the blankets in the rocket that brought him to Earth), the post-Crisis Superman's costume was made of ordinary material. Since the post-Crisis Superman possessed an invisible "aura" that surrounded him and contributed to his invulnerability, objects held close to him, such as his costume, were protected from harm; his cape, meanwhile, could (and did) easily sustain damage in battle.
Kal-El was not an infant sent from Krypton to Earth; rather, his fetus was placed in a "birthing matrix" equipped with a rocket engine and Jor-El's experimental warp drive, with Kal-El gestating during the trip to Earth; once the rocket landed, Kal-El was fully "born" on Earth.
Superman was made the sole survivor of Krypton's destruction (vs. the earlier version having other survivors such as Supergirl, Krypto, etc. attached to him).
Clark's abilities developed gradually in the yellow sun environment, starting with resistance to injury, then strength, x-ray vision, etc., with his ability to fly being the last to emerge. It took until his late teen years for all of his powers to develop; thus, Clark only adopted the Superman identity in adulthood, and never was Superboy.
Clark's adoptive Terran parents, Jonathan and Martha Kent are alive and well in Clark's adulthood, and Clark visits them periodically. (Previously, they had died shortly after Clark's high school graduation).
Lois Lane was written as an aggressive reporter and person from the start, and never expressed a desire to find out Superman's secret identity.
Superman's arch-nemesis Lex Luthor was no longer a mad scientist but instead a power-hungry billionaire, "the most powerful man in Metropolis," who resented Superman's overshadowing presence. Instead of battling Superman directly, Lex would use hired minions and staff on his payroll to confront Superman directly using whatever schemes or devices Lex had in mind.
The villain Bizarro was established as an imperfect clone of Superman, created from the superhero's DNA, rather than as a duplicate from an alternate universe.
Lana Lang and Jimmy Olsen lost all of their superhero identities.
All of the variant forms of kryptonite (red, gold, yellow, blue, white, etc.) no longer existed. Only green remained.
Superman's relationship with Batman, which was much closer pre-Crisis, became much more tentative, as each disagreed with the other's methods and attitudes.
Superman had no memory of his existence on Krypton, but instead identified himself as a citizen of Earth.
Two of the most important changes made to Superman's personality included:
Superman's alter-ego Clark Kent was no longer "mild-mannered"; he became more assertive, and an important half of a double life. Man of Steel established Clark Kent as the "real" person, with Superman being the "disguise" - a reversal of the earlier canon.
It was not known to the general public that Superman had a secret identity, since he didn't wear a mask.
