If the patient has one or more abnormalities, such as blurred vision when looking at a distance, clear vision when looking at near vision, the ability to immediately improve clarity by squinting the eyelids, slight distortion of the straight line at the edge of the field of vision, and the appearance of a diffuse halo around the point light source at night, we should Consider astigmatism. Second, the use of radiometric vision chart for self-testing, relatively accurate, the specific test method is to download and print the radiometric vision label, then the right eye first, then the left eye, each time a separate check only one eye, eyes fixed on the black dot in the center of the radiometric vision label, observe whether the degree of clarity of the anti-radiation in all directions, if the degree of clarity is not consistent, some lines of black color, some lines of light color, indicating the presence of astigmatism presence.