Jesus, how stupid can Clary be? It’s only logical to assume he’s not wearing the glasses because Vampires have heightened senses and that includes enhanced seeing. This actually goes to a bigger problem about this whole situation. Clary acts like she has never read a book that vampires in it or hell I would even take a vampire movie at this point. Actually, this bullshit because Clary did watch a vampire movie in this book. She did back in Chapter 2 when Clare was writing that bullshit scene where Simon freaked over a vampire scene. She tried to mimic Bela Lugosi’s voice.
I can buy that other people are not super into folklore and mythology like I am, or hell even watched a hell of a lot of vampire media like I have (Don’t get me started on Buffy, Angel, Underworld, and Forever Knight guys or I will never shut up). However, a lot of vampire lore in this universe is basic vampire lore that has practically been over saturated into pop culture. Yet, Clary doesn’t seem to know anything about what abilities or vulnerabilities a vampire might have.
In the end, this passage really just made Clary look even more like an utter idiot.