0.75 is just a number, and if it is expressed in terms of more than one degree, a plus or minus sign must be added, or axial to indicate the degree. For example -0.75 DS indicates 75 degrees of myopia, and if it is +0.75 DS, it indicates 75 degrees of hyperopia. If it is 0.75 x 1 axial, it means astigmatism. So 0.75 just represents a number that is not necessarily related to the number of degrees. The refractive examination of the eye is mainly composed of three aspects: spherical lens power, column lens power and astigmatism power. In addition to checking the eye axis and corneal curvature, from these aspects can reflect a person’s complete refractive state, according to the refractive state to determine whether it is normal or abnormal, the need for prescription treatment.