Astigmatism is a refractive irregularity of the eye related to the curvature of the cornea. Astigmatism is caused by an inconsistency in the refractive index of the meridians of the refractive system, which prevents light rays passing through these meridians from converging at the same focal point. As a result, the light rays cannot be accurately focused on the retina to form a clear image, a condition known as astigmatism. Astigmatism is divided into myopic astigmatism, hyperopic astigmatism and mixed astigmatism. Astigmatism harm: 1, cause amblyopia. 100 or more astigmatism can cause amblyopia, the higher the degree of astigmatism, the more serious amblyopia. 2, caused by the partial head to see, squinting to see, squint. Astigmatic amblyopia treatment: 1, wear astigmatic lenses: 75-100 degrees above should wear lenses, all day wear. 2, amblyopia instrument treatment: after treatment can slow down the incidence of amblyopia. The earlier the astigmatic amblyopia is treated, the better the effect of amblyopia treatment.