In "The Sword of Summer" by Rick Riordan, the protagonist describes his unique gray eyes, noting that they resemble those of his cousin Annabeth rather than his mother's. This observation highlights a connection between characters, emphasizing familial similarities that deepen their relationships. The comparison also signifies how physical traits can help establish identity and lineage within the story. Furthermore, such descriptions contribute to the rich character development in Riordan's work. By focusing on specific features like eye color, the author characterizes protagonists in a way that readers can visualize and relate to them. This attention to detail not only enhances the narrative but also enriches the reader's understanding of the characters' backgrounds and connections.