Shmoop. - The Bluest Eye by Toni Morrison

The title has at least two meanings, referring both to Pecola's desire to change the way she is seen and the way sees.
Let's deal with the easy one first. As a black child growing up in1940s America, Pecola associates beauty with being white and having blue eyes, like child icon Shirley Temple. Pecola seems to be OK with her nose and mouth, even her hair - but her eyes, oh, her eyes! She thinks that if she could just have those bright blue eyes, she'd become truly beautiful and no one would ever tease her at school, her parents wouldn't fight anymore, and she'd never be sad again.
Now, onto the second aspect of the title - Pecola's desire to see the world differently. Pecola believes that if her eyes were blue, she would begin to see the world the way that white children do - she would get to be innocent, she would experience a loving family.
A third idea plays with the meaning of "blue" as "sad." Pecola's eyes already are the bluest in the book, in that they are the saddest eyes, possessed by the most tragic character in the novel.

It's easy to read the final chapter quickly, since it consists mostly of rapid dialogue between Pecola and what appears to be an imaginary friend. But when we slow down and read more closely, we see how this conversation speaks to two of the major themes in the book - Appearance and Society and Class.
First, this chapter highlights the fact that Pecola's obsession with beauty has evolved throughout the novel. By the end, "blue eyes" are no longer simply code for Shirley Temple or white beauty; rather, they are how Pecola makes sense of the rape she has endured.
Pecola convinces herself that the reason no one talks to her and the reason her own mother can't make eye contact with her is because everyone is jealous of her eyes. It's just too hard, and Pecola is too darn young, to admit that the real reason she is being ignored is because she was raped by her father and delivered his child.
When you think about it, this is actually a realistic portrayal of the way children (and hey, some adults too) deal with cruelty and teasing. In this chapter, it's as if Pecola is shouting, "You're just jealous!"
We also see the consequences of relying on physical beauty to make up for psychological and social problems. If beauty is being used to cover up ugliness, and the world keeps doing ugly things to you, then beauty can never be enough to fight that. Even though Pecola has, in her delusional mind, received blue eyes, she now wonders obsessively, "what if there's someone with bluer eyes?" There will always be someone out there more beautiful than you, and Pecola seems to be an example of how crazy you can get if you don't face this fact.
Finally, the ending reminds us that Pecola's "madness," if we want to call it that (do we?) is not her fault but is embedded in her community. The chapter begins with a quote from the initial Dick and Jane grammar school primer that is the book's epigraph, at the point in the story where a "friend" comes to play with Jane. The epigraph says, "THEYWILLPLAYAGOODGAME." It's painfully ironic that this excerpt foregrounds the theme of friendship. Pecola doesn't have any real friends, only this voice inside her head.
Now, calling this second voice an "imaginary friend" is maybe a bit too easy. It might be more interesting to see the second voice as the part of Pecola that still wants to live. After all, this is an affirming voice, an encouraging voice, one that wants her to go outside and to help her address the aftermath of the rape.
Perhaps the true tragedy of the novel is that in ignoring her completely, Pecola's community forces her into such devastating loneliness that she has to imagine someone talking to her. The community commits a crime on a par with Cholly's abuse: if Cholly failed her by raping her, Pecola's community failed her by never acknowledging that a rape took place.

Morrison is famous for her use of fragmented narrative with multiple perspectives. Her use of different narrative styles - alternating between first- and third-person omniscient - gives her the freedom to do two interesting things. On the one hand, she uses Claudia to convey the thoughts and perceptions of a 9-year-old girl, giving the novel an aspect of innocence. On the other hand, the use of third-person omniscient narration allows the novel to cover broad sweeps of time and space - like when we get the history of the Breedloves' storefront or stories about Soaphead Church's white ancestors. This opens the novel up, giving it historical depth, and allowing us to see how the racial issues of the past are still impacting these characters in the 20th century.