There's no specific in-universe explanation for the prevalence of glasses, but it's likely due to a combination of factors:
* Visual Style: The art style of Persona 4 leans towards a more realistic and detailed aesthetic, and glasses can be a feature that adds to the characters' individuality and visual appeal.
* Stereotypes: Glasses are often associated with intelligence and studiousness, which fits the overall theme of the game as a coming-of-age story about high school students.
* Character Design: Individual characters' personalities and backgrounds may have influenced their wearing of glasses. For example, glasses can emphasize the studious nature of characters like Yosuke or the reserved demeanor of Yukiko.
It's important to remember that not all characters in Persona 4 wear glasses. For example, Protagonist, Junpei, and Naoto are notable exceptions. Ultimately, the choice of whether or not to wear glasses is a design decision for each individual character.