Astigmatism is a type of refractive error, usually caused by developmental abnormalities or prolonged unhealthy eye habits. Astigmatism is a type of refractive error, which is usually caused by abnormal development or long-time unhealthy eye habits, such as squinting for a long time to see things, it is easy to press the top and bottom of the cornea, changing the curvature of the cornea, thus causing astigmatism. Under normal circumstances, there should not be any astigmatism, as long as there is astigmatism in the results of the optometry, it means that it is not normal, but only a lower degree of astigmatism, for example, less than 50 degrees of astigmatism, usually does not have an impact on vision, and can be left uncorrected and untreated. If the astigmatism is high and affects the patient’s vision, it can be treated with glasses or laser surgery.