The clinical manifestations of myopia are varied: mild myopia is used to blurred distant objects, and because it is very clear to see near, it can adapt to life, study and work without feeling restricted. It is only when there is a need to see far away, or when comparing with normal sighted people, or when health examination, it will be noticed. Generally, they complain of blurred vision or “nearsightedness”, such as difficulty in seeing the blackboard or distinguishing road signs. Once they put on corrective glasses, they are amazed that a different world appears before their eyes. Some people who have myopia at an early age, because of the obvious low vision, usually prefer to live indoors, alone, so that the personality tends to be more introverted. 2. In order to reduce the hazy image formed by the diffuse aperture of the eye, many myopes improve their vision by narrowing the lid fissure and increasing the depth of field, so they often show habitual squinting movements. Myopia is usually characterized by a large, full, proptotic eye. When the eye is turned extremely inward, the equatorial part can appear in the lid fissure area, and this phenomenon is more obvious in those with high myopia in one eye. 3. Flying mosquito phantom vision or flysightedness is a common complaint in highly myopic eyes. This is due to high myopia is complicated by vitreous degeneration, liquefaction, clouding of the formation of fine floaters, projected on the retina, and cause the phenomenon of floating black shadow in front of the eyes. There are many different forms depending on the location, size and number. It can be dotted, linear, reticular, or cloudy, as if there are mosquitoes or flies flying in front of the eyes. The number varies, sometimes faint, uneven density, some light and some thick. It can be seen in all types of myopic eyes and can appear early or late. It generally increases slightly with age. When the attention is distracted, or long due to adaptation and habit, flying mosquitoes (flies) can not be detected. Usually does not affect vision, but some patients are very sensitive to this, often for the immediate anomalies and trouble. Mild myopia more than no such symptoms. 4. Usually myopic patients can experience some abnormal sensations and visual fatigue after using their eyes too much. Most often seen when there is astigmatism, refractive error, or poor general condition. Such as visual distortion, double vision, small vision (especially when wearing high diopter glasses), flash, discoloration, photophobia, eye dryness, eye itching, eye foreign body sensation, heavy eyelids, eye pain, headache and inability to read for a long time. Possible reasons for these phenomena: ① myopic eyes have a dysfunctional relationship between the adjustment and the collection function, resulting in adjustment tension and strabismus; ② highly myopic eyes have a small range of adjustment and have difficulty adapting to changes in distance when reading too close; ③ improper prescription (e.g., overcorrected refraction, oversized frames, wrong pupil distance, etc.). 5, the formation of amblyopia, mostly seen in early childhood onset of high myopia, treatment is based on wearing glasses, as long as the fundus is normal most of the results are very good. 6, fundus lesions; mostly seen in highly myopic people, manifested as leopard-like fundus or even peripheral retinal degeneration and more likely to lead to retinal detachment when suffering from trauma, etc.