The 1224 cataractous patients who had extracapsular cataract extraction and posterior chamber lens implantations were evaluated retrospectively irrespective of style, postoperative position of intraocular lens and surgeon. The 100 cataractous patients who had extracapsular cataract extraction and posterior chamber lens implantations in the bag accurately using single lens style by one surgeon(E.H.L) were evaluated prospectively. And then the predictive accuracy of the SRK/T intraocular lens power calculation formula was compared with other formulas (SRK, SRKII and Holladay) without consideration of individual A constant. The SRK/T formula was more accurate than other 3 formulas in all axial length, but there were no significant differences statistically. Especially for short and long eyes, SRK/T formula was more accurate than other 3 formulas.