It's a common misconception, likely stemming from:
* The "wizarding world" aesthetic: The image of round, slightly mismatched glasses held together with tape fits the image of a slightly neglected, quirky wizard.
* Visual representation: In the movies, Harry's glasses do have a worn and slightly crooked look, which could be interpreted as needing tape.
* Fan art and cosplay: Many fan artists and cosplayers choose to depict Harry with taped glasses, further perpetuating the idea.
However, in the actual canon, Harry's glasses are just worn and in need of some TLC, not actually held together with tape.