Uglies by Scott Westerfeld

Uglies is a 2005 science fiction novel by Scott Westerfeld. It is set in a future post-scarcity dystopian world in which everyone is turned "Pretty" by extreme cosmetic surgery upon reaching age 16. It tells the story of teenager Tally Youngblood who rebels against society's enforced conformity, after her new found friends Shay and David show her the downsides to becoming a "pretty". Written for young adults, Uglies deals with adolescent themes of change, both emotional and physical, and dealing with the revelation that "some of what you’re taught isn’t true, your parents are flawed human beings and the world isn’t constructed for your benefit." The book Uglies is the first installment in what was originally a trilogy, The Uglies series which includes Pretties and Specials and Extras... The Uglies series is set at least a few centuries in the future, after current civilisation was destroyed by a bacterium which de-established all petroleum products, causing widespread chaos. The survivors of this disaster established cities much smaller than those currently existing, each of which is independently governed with limited traveling. At the age of sixteen, each person undergoes an operation which boosts their immune system and reflexes while giving them well-proportioned, symmetrical faces based on an international standard, so that all pretties look nearly identical. Later operations follow to show signs of increasing age while maintaining this beauty. Before they receive the operation, children are referred to as "uglies", and are kept separate from their older friends... (Summary by Wikipedia)