There are many causes of myopia, mainly the following two: First, more sweets More sweets will contribute to the development of myopia. Because the metabolism of sugar in the body requires a lot of vitamin B1, it will reduce the level of calcium in the body, thus weakening the elasticity of the eye wall and leading to the deepening of myopia. Therefore, adolescents with myopia should eat as few sweets as possible. The intake of too much starch will make the body’s insulin rise, leading to uncontrolled growth of the eye axis, prone to myopia; excessive intake of MSG will reduce the body’s iodine, affecting retinal development; frequent consumption of smoked and overcooked protein-based foods can make the body’s calcium metabolism abnormal, which is not conducive to the body’s maintenance of normal intraocular pressure and eye wall hardness, also prone to myopia. Therefore, three meals a day light and delicious, conducive to the prevention of myopia. Secondly, eating hard food too little hard food is also one of the reasons for the increase of myopia in teenagers. Eating food prompts the facial muscles to move, including the muscles that govern eye movements. In turn, the ability to regulate the lens of the eye effectively. Japanese researchers investigated nearly 300 students for this purpose, who like to eat hard food vision are normal, often eat soft food vision more than varying degrees of decline, so chewing such as carrots, potatoes, soybeans, fruit and other chewy hard food, increase the opportunity to chew, can prevent the occurrence of myopia.