I originally heard of this book from my school teacher, what was long time ago. I do not even remember the context and why had the topic been risen.
I only remember some plot details:
Some group of space travelers found a planet that abounded with human beings, I do not remember what had happened to the whole crew, but I remember that one of the crew members decided to stay there, and he was accepted by the planet population very well. He got married there and so on, got normal life. But one day he noticed, that his perfect beauty wife is not perfect at all, she is wounded and ugly. He decided it to be a glitch and went to the doctor. Doctor gave him some kinda of pills and after the course his "disease" had been stopped. But not so long after the story repeated and he had to go to the doctor again. Sitting here and waiting for an audience he had a conversation with some local guy, who told him not to take pills and see what gonna happen. And he decided to stop taking pills. After all he finds out that the whole planet's population had been attacked by space invaders, that all the "people" there are ugly, they had survived some kind of nuclear war, that they all are taking pills to hide from reality and make their lives colorful, and that they even do not have the sun, they live under the large concrete dome which protects them from the radiation...
I do not remember ongoing plot, hope someone will be able to recognize :(