Do you think Eridan has bad eyesight or he wears his glasses just to be a nerd?

Hard to Tell, it’s easy to tell with the Humans because they were born with Glasses, but Trolls are Grubs at birth, so the fact none of the Grubs have Glasses either means they’re all nerds that wear glasses for fashion, or that they don’t need glasses until after they’re not squishy grubs.