Patients need to be clear that medical optometry is not able to get the degree of myopia, the so-called degree refers to the degree of wearing glasses, there is no direct link between visual acuity and degree. Generally, the measured visual acuity is the bare eye visual acuity, that is, the level of visual acuity without glasses, the normal should be 5.0, that is, the international standard of visual acuity 1.0 visual acuity, 4.8 is equivalent to the international standard of visual acuity 0.6 visual acuity, belongs to myopic eyes. Usually myopic 4.8 patients need to wear about 150 degrees of glasses to correct their vision, taking into account the astigmatism and other refractive errors, but also need to adjust the astigmatism degree when prescription glasses. Therefore, patients need to choose the right glasses under the guidance of a professional optometrist or dispensing doctor. Too high a prescription can cause dizziness and aggravate myopia and cause eye fatigue, while too low a prescription will not achieve the purpose of correcting vision. For those who have already caused myopia, while wearing glasses, you still need to pay attention to the healthy use of eyes, avoid watching TV, playing cell phones, studying and working in a dim environment, keep a suitable distance, reduce the occurrence of excessive use of eyes, combine work and rest, and ensure rest. In your free time, you can relax your eye muscles and nerves by doing eye exercises and outdoor sports to relieve eye fatigue and slow down the development of myopia. Moreover, animal liver, mangoes, spinach, carrots and other fruits and vegetables are rich in vitamins and proteins that help protect vision. In addition, cataract, glaucoma, diabetes, fundus lesions, eye tumors and other diseases may cause vision changes, and patients can also improve the examination and active treatment under the guidance of doctors.