Refractive spherical lens S and refractive cylindrical lens C refer to degrees of hyperopia, myopia and astigmatism respectively, where spherical lens S can be used to correct myopia or hyperopia and cylindrical lens C can be used to correct astigmatism. Spherical lens S in an optometric examination indicates the degree of myopia or hyperopia, where myopia is indicated by “-” to correct myopia and hyperopia is indicated by “+” to correct hyperopia. Column C refers to column lenses, which are used to correct astigmatism, where myopic astigmatism is indicated by “-” and hyperopic astigmatism is indicated by “+” to correct myopic astigmatism and hyperopic astigmatism, respectively. In addition to the number of diopters, cylindrical lenses also have an axial position. Axial position refers to the axial direction of the astigmatism, which is usually indicated by A. If the patient has a certain number of degrees of both spherical lenses and cylindrical lenses, it may be necessary to use a combination of spherical lenses and cylindrical lenses for correction. It is recommended that patients with refractive errors visit the hospital in a timely manner to have their condition evaluated and treated under the guidance of a physician.