Sight plays a role in Holding Up the Universe as Jack’s prosopagnosia—his inability to recognize faces—continues to become a more significant threat to his character and the characters around him. Jack literally cannot recognize most people, and not only does this result in uncomfortable social missteps for him, he also sees it as a threat to his own identity at Martin Van Buren High School. He worries that if his condition were to ever become known, he would lose his identity as the popular, charming, flawless Jack Masselin. The same is true for Libby, as well. Once known as “America’s Fattest Teen,” the beginning of the novel sees Libby returning to school for the first time in years. Even though she has lost a considerable amount of weight, Libby is still obese, and she worries that her classmates will only see her weight, not her true self.

In a more metaphorical sense, Holding Up the Universe asks readers to consider what it means to “see” someone and to be “seen.” Niven points out that we often see people superficially, but what really matters is seeing the truth of a person and who they are on the inside.