For the most part, readers tend to assume that they are the intended audience when reading any text. Under some circumstances, the author's intended audience can be either implied or announced. In regards to Toni Morrison's The Bluest Eye, the intended audience is subtly referred to in the forward of the novel.
Essentially, her novel speaks to everyone. Morrison states that she is certain that, at one time or another, everyone has felt disliked. Some people even know what it feels like to be hated (for things "we have no control over and cannot change"). Morrison, therefore, wanted to look at those who found themselves debilitated by hatred.
Morrison, according to the forward, wanted to "enter" into the life of one who was unable withstand the "damaging forces" associated with youth, gender, and race. Morrison wanted her audience, Claudia's audience, to understand self-loathing and beauty.