What is a metaphor in Act 2, scene 2, of Romeo and Juliet that supports the theme that love can damage a person's perspective?

Almost as soon as the scene begins, Romeo spies Juliet's balcony which overlooks the garden, and he says, "But soft, what light through yonder window breaks? / It is the East, and Juliet is the sun" (2.2.2-3).  This is actually two metaphors: he compares the window to the east, the direction from which the sun rises each morning, and he compares Juliet to the sun.  The sun is literally the center of our solar system, a system which could not function were it not for the sun's heat and light.  Romeo seems to be saying, then, that Juliet is as important to his life as the sun is to human life and that he would not be able to exist without her.  However, to be fair, they have only just met that night, and his life is not literally dependent on her.  His intense feeling, intense enough to construct such a metaphor, that his life is dependent on her position in it, certainly helps to convey the theme that love can damage a person's perspective.