Atropine is a powerful mydriatic drug that is sometimes used in eye exam. When used at normal concentrations, the pupils will remain open for a few days to a week. The myopia-suppressing effect of atropine has been known for a long time, but it could not be used because it was dazzling while the pupils were open and it was difficult to read things. It was found that when this was diluted to a very thin concentration, the pupil did not remain open, but it had the effect of sup