Shall I compare thee, My mistress eyes comparison

Shall I compare thee to a summer's day (sonnet 18)
My mistress eyes are nothing like the sun (sonnet 130)

         Both Shakespeare's "Sonnet 18" and "Sonnet 130" follow the traditional model for English sonnets.  The have the abab cdcd efef gg rhyme scheme in iambic pentameter which naturally creates three quatrains and an heroic couplet. They both deal with the topic of the poet's lover, but Shakespeare's treatment of his lover is completely different in the sonnets.
          "Sonnet 18" is very traditional in that it praises the woman the sonnet is about. The first line is a rhetorical question: "Shall I compare thee to a summer's day?"and the rest of the poem answers the question. The sonnet praises the woman, saying she is "more lovely and more temperate."  The poet says that she is more beautiful and unchanging than summer because while summer can have days that are too hot or days that are cloudy, her beauty is never "dimmed" and she remains beautiful. Shakespeare goes so far as to say that his love's beauty is eternal and she will never die.  The concluding couplet says that "as long as men can breath or eyes can see," her beauty will live on as people from future generations read this sonnet and hear her beauty described.  This kind of ideal, romantic praise is typical subject material for a sonnet.
          In contrast, Shakespeare's "Sonnet 130" is like an anti-sonnet. While it still contains three quatrains and a couplet and maintains the English sonnet rhyme and rhythm, it doesn't focus on praising the woman. Instead this poem states that nature is more beautiful than the mistress.  Her hair is "wiry" and her skin is "dun."  Poets traditionally praise their ladies scent, but she "reeks" and she does not glide with the grace of a goddess but rather "treads on the ground."   This woman receives a very different and far less pleasant treatment than the woman of "Sonnet 18".  However, in the last two lines Shakespeare redeems himself, and his love, by stating that he loves her because of these faults and not in spite of them.  She is a real woman and his love for her is not blinded, but genuine.
          Shakespeare's "Sonnet 18" was written early on in his sonnet sequence, and he glorifies the woman he writes about and put her above a summer's day. Shakespeare's "Sonnet 130" was written much later in his sonnet sequence, and in this he puts nature above his mistress. It is interesting to compare how previously he was overstating the beauty of the woman, because he saw her as perfect, but then later he states the mistress's flaws outright, embracing them as a part of her, and loving her because of them.