The fact that a 10-year-old patient has 300 diopters of myopia does not predict how many diopters he or she will be able to progress to by the time he or she reaches the age of 18. A myopia of 300 diopters in a 10-year-old patient is relatively serious, usually due to genetic factors or long-term bad eye habits. If the patient does not have timely intervention, the myopia will likely continue to grow in later years, but there is no way to predict the rate of myopia growth, so it is not possible to know how many diopters of myopia will have progressed by the age of 18 years old. The patient should pay attention to strictly control the time of close eye use every day, do more outdoor exercise, try to relax and rest the eyes, in order to effectively inhibit the growth of myopia. If myopia is high, early correction is recommended.