Whether it is appropriate to wear 275-degree glasses for 300-degree myopia is based on the results of the trial. If the patient is able to achieve a corrected visual acuity of 1.0 by wearing 275-degree glasses and is comfortable with his/her visual acuity, then it is appropriate, and vice versa, it is not appropriate. The purpose of myopic patients wearing glasses is to improve visual acuity, but patients can not be directly based on the results of optometry to test glasses, but also to further trial lenses, that is, in accordance with the results of the preliminary optometry to try on the lenses to observe the visual acuity to improve the situation, as well as dizziness, ghosting and other symptoms of discomfort, and to further fine-tune the prescription number. If the patient is 300 diopters myopic and tries on 275 diopters lenses, the corrected visual acuity can reach the normal 1.0 and there are no discomfort symptoms, then it means that it is suitable, and generally wearing slightly lower lenses than the actual number of diopters will help to alleviate the patient’s discomfort of visual fatigue when using eyes at close range. However, if a patient with 300 degree myopia wears 275 degree glasses, the corrected visual acuity can not reach normal, it is necessary to further increase the number of degrees, with the full number of degrees, otherwise it is not conducive to the health of the eyes. It is recommended that myopia patients seek timely medical attention to assess their condition and follow the doctor’s instructions to choose the appropriate treatment and care.