What is myopia? In short, myopia is seeing close and not far. The eye can be compared to a camera, the cornea and the lens are compared to the lens, and the retina in the fundus is compared to the negative in the dark box. If the mirror box is too long or the lens is too thick, the distant image can only be focused in front of the negative, and the image will not be clear. In myopia, the light entering the eye can only gather in front of the retina due to the enlargement of the eyeball, the long anterior and posterior diameters (eye axis) or the excessive refraction of the light medium in the eye (crystals, etc.), thus blurring the vision. Myopia is a problem that cannot be ignored because it not only affects learning, but also employment. How do you get myopia? Most myopia is caused by improper eye protection, and a small percentage is inherited. Since genetic engineering cannot be used to modify genes, the focus of myopia prevention and treatment should be on improving the visual environment.