If the eyes do not see distant objects clearly, it is usually due to refractive error, including myopia, hyperopia or astigmatism. Therefore, after this situation, it is important to go to the hospital as soon as possible for vision and optometry examinations, which can accurately understand the refractive state of the eyes and clarify whether there is myopia, hyperopia or astigmatism. If it does exist after the examination, the refractive error can also be accurately understood after the optometric examination, and early prescription of glasses to improve vision, in order to maintain a clear visual quality in ordinary times, to avoid eye fatigue. Refractive error is a very common disease in ophthalmology, especially in children and adolescents, and is generally considered to be related to eye habits or congenital developmental abnormalities. Therefore, it is important to pay attention to maintain reasonable eye habits in general.