Which theme is the "eye" motif related to?

Eye contact seems to be related to confidence and power in this story. Mama says early on that Dee "would always look anyone in the eye." Moreover, when Mama describes what Dee was like as a child and a young woman, she says that Dee "was determined to stare down any disaster. . . . Her eyelids would not flicker for minutes at a time." Maggie, on the other hand, seems to be incapable of making eye contact. Mama describes her as "chin on chest, eyes on ground, feet in shuffle." Then, when Dee comes home, her dress is "so loud" that Mama says "it hurts [her] eyes." Dee covers and uncovers her eyes with sunglasses, holds up a camera before her eyes to take pictures, and even sends "eye signals over [Mama's] head" with Hakim-a-barber.
Dee overpowers her mother and sister up until the final moments of the story when Mama refuses her request for the quilts. Dee often conveys her power over them, and over everyone else, with her eye contact: she can exercise it or withhold it and assert her power when she chooses. In other words, then, one can assert one's power by making or refusing eye contact with others.