[AlexanderHowl]

I think that since Bad Sight is quite common in real life, so it ends up appearing in a lot of characters in fiction because it is a disadvantage that someone can live with without major issue (eye glasses are not that hard to keep safe day-to-day and extra pairs are relatively cheap). It is also a stereotypical disadvantage for intellectual characters, so it tends to be an easy fit for most intellectual characters in modern settings.