Astigmatism and myopia are both common eye diseases and are two different types of refractive errors. Under the same degree of refractive error, astigmatism can cause more damage to visual function than myopia. This is because patients with astigmatism usually experience abnormal development of the cornea, leading to different refractive powers in different directions. As a result, when light passes through the cornea and enters the eye, it cannot converge to form a single focus, but instead forms a line intersection, which greatly affects the quality of vision. On the other hand, myopia is caused by an overly long eye axis or excessive corneal refractive power. When light passes through the cornea and enters the eye, although it cannot focus accurately on the retina, it can still form a focus. Therefore, the impact on vision is less severe than that of astigmatism.