What if someone decided that contacts were stylish and banned those
It already happened. This is from a YNet article titled “Rabbi, how do you like my glasses?”.
In a special sermon to the young yeshiva students of the Hasidic dynasty, considered one of the biggest in the haredi sector, Rabbi Israel Hager, the successor of the Vizhnitz Hasidism’s founder, discussed the dangers inherent in modernizations on the secular street and urged the students not to wear metal glasses and contact lenses.
The rabbi made the remarks as part of the Shovevim period – an acronym for the Jewish weekly Torah portions of “Shemot”, “Va’era”, “Bo”, B’Shallach”, “Yitro” and “Mishpatim”. During this period, it is customary to be more careful not to violate any of the sex-related transgressions commanded in the Torah and study the laws relating to such transgressions.
Rabbi Hager said in his sermon that the students must “beware of the dangers hiding on the street.” He added that, “a student who wishes to delve into Torah studies and observe mitzvot must detach himself from all nonsense and not let them infiltrate.”
The rabbi called on students wearing modern metal glasses to remove them and move to anti-modern plastic glasses. Rabbi Hager also spoke out against yeshiva students wearing contact lenses.