People have always believed that vision loss starts unknowingly, and by the time they or their families discover it, they already regret it. In fact, the onset of myopia has precursors and signals, and it is important to understand the precursor symptoms of myopia in order to strengthen prevention in a timely manner. Ophthalmologists call the symptoms before the onset of myopia “myopia precursor syndrome”, which often has the following manifestations. 1. Eye fatigue. When looking at books and reading for a long time, the words overlap serially, or look up at the object in front of you, there is a sense of as if, floating unstable, you have to pay attention to it. If you look at a near object after looking at a far object for a long time, or look at a far object after looking at a near object for a long time, you will experience a short period of blurred vision. These are signs of ciliary muscle dysregulation, caused by eye strain, and are the “prelude” to myopia. In addition, recurrent chalazion, mydriasis, or blepharitis, although the visual acuity can reach more than 1.0, is often the beginning of myopia. 2. Perceptual allergy. Eye fatigue is accompanied by burning, itching, dryness, swelling and pain in the eyes, and in severe cases the pain radiates deep into the orbits and even causes migraine headaches, as well as soreness in the occiput, neck and back of the shoulders. This is due to the fatigue perceptual allergy of the sensory nerves in the eyes. 3. Systemic nerve disorder. Suddenly, those who had good grades become bored with learning, have a scattered attention span when listening to lectures, are somewhat slow to respond, become easily irritable, lack interest in things they used to love, and their academic performance decreases. At night, he or she sleeps a lot, sweats a lot, is easily tired, and has dizziness and loss of appetite. These changes are also signs that myopia is occurring. Forty percent of the precursory symptoms of myopia first manifest in the sensitive trigeminal and autonomic nervous systems. The first sign of myopia is not a loss of vision, but rather a neurological symptom. Myopia is not just a problem of the eyes, but is associated with systemic changes.