ASTIGMATISM DEGREE OF TORIC TYPE EYE LENS AND METHOD FOR DETERMINING DEGREE OF EYE LENS

摘要

PURPOSE:To obtain the astigmia degree of a toric type eye lens capable of remedying astigmia before operation and a method for determining the degree of the lens by converting the data of corena astigmia degree before operation to the astigmia degree of the eye lens. CONSTITUTION:In a toric type eye lens 10, the eye lens degree of an optical part 12 is determined to enable the remedy of astigmia before operation. The spherical surface degree P1 of the eye lens 10 is obtained from the data R1 of corena radius of curvature in a strong principal meridian direction or the refractive power data K1 of the corena. Also, te peripheral surface degree P2 of the eye lens 10 is obtained from the data R2 of corena radius of curvature in a weak principal meridian direction or the refractive power data K2 of the corena. Then, P1 is deducted from P2, thereby obtaining the degree of circularity P3. In addition, the strong meridian direction is used as a corena axis and P1 is used as the peripheral degree of the eye lens 10. Also, P3 is used as the corena degree of the lens 10. The eye lens 10 set as aforementioned is inserted into an eye, according to the same method as in the conventional operation.