Astigmatism is actually crucial in optometry, if the astigmatism is not correct, the accuracy of the spherical lens will not be accurate anyway, you can use the corneal curvature meter, astigmatism table, slit film method, crossed cylindrical lens astigmatism method for detection, as follows: 1, corneal curvature meter: the most common corneal curvature meter can check the corneal astigmatism, now some of the more high-end computerized optometry can also measure the corneal astigmatism. 2, astigmatism table: this is a rough examination, which line is seen most clearly in the dial, use this line corresponding to the smallest Arabic numeral multiplied by 30. The most accurate method is the crossed cylindrical lens astigmatism method: the most accurate is the crossed cylindrical lens astigmatism method, the accuracy is higher. method, the accuracy is relatively high, and in the end it still depends on it to adjust the axis position and degree of astigmatism.