Astigmatism of 100 degrees is mild astigmatism, which is not serious, and it is important to correct it in time to prevent the increase of the degree. Astigmatism is a relatively common ophthalmic disease, a kind of refractive error, often combined with myopia or hyperopia, mainly caused by congenital genetic and acquired eye diseases. It manifests as blurred vision, double vision, and varying degrees of visual fatigue. Experts recommend that astigmatism greater than 75 degrees should be corrected, timely correction of astigmatism can not only enhance visual acuity, the main purpose is to eliminate visual fatigue. On the contrary, if astigmatism is not corrected, in the long run, its visual fatigue and blurred vision will stimulate the elongation of the eye axis, which will accelerate the development of myopia and further damage vision. At the same time, some acquired astigmatism can be prevented by good eye habits: 1. no eye rubbing, no squinting, no lying down to read; 2. intermittent eye use, after every half hour of close eye use, rest for about 10 minutes or look into the distance; 3. reasonable diet, more outdoor activities, regular eye examination and health care. In conclusion, astigmatism of 100 degrees is not serious, as long as it is corrected as early as possible, good eye habits are developed, and regular eye examinations and health care are carried out.