Myopia is a medical condition in which a person cannot see objects in the distance clearly. (1) It is very common and people are likely to become myopic if they do not pay attention to it. It brings many problems to people in daily life. Many people are embarrassed because the glasses will stay with them their whole life. “Estimates of the number of people suffering from refractive errors worldwide range from 800 million to 2.3 billion. » (Dunaway D, Berger I. "Worldwide distribution of visual refractive errors and what to expect in a particular location.") (2) Myopia is ubiquitous and troublesome due to many causes, but it can be prevented from several ways. The different reasons why people become myopic are overuse of the eyes, bad habits and heredity. If a person works with the eyes for a long time, he will experience eye fatigue and cause damage to the eyes. He will experience dry eyes and eye fatigue. When people view an object closely or read books, cell phones, computers in an inappropriate position, such as a moving vehicle and dark places, they damage their eyesight. heredity...