In general, the following signs are usually present when a teenager experiences vision loss and becomes nearsighted: ① Symptoms of eye fatigue. Specific manifestations include: feeling heavy shadows and floating instability in handwriting when reading books. Frowning when looking at things, and sitting forward when watching TV. Some people will experience a brief blurring in front of their eyes when they move to near objects after looking at far objects for a long time, or when they move to far objects after looking at near objects for a long time, which is the deepening of eye fatigue and the approaching time of myopia. ② Perceptual allergy symptoms. Many people have dry, itchy eyes and eye swelling pain after vision loss. In some cases, the swelling and pain may spread to the deeper part of the eye orbit, and in some cases even cause migraine. and soreness in the back of the neck and shoulders. The above symptoms, if detected early, can be corrected with proper eye use. If the above symptoms are detected early and corrected in time, myopia can be nipped in the bud and our eyes can be protected.