1. A method for calculating the center of an anterior capsule of the crystalline lens of a patient for a cataract surgery, comprising the steps of: imaging a patient's eye with optical coherence tomography; generating a 3-dimensional (3D) image and coordinates based on the data obtained by the optical coherence tomography; capturing an image of the patient's eye; and calculating the center of an anterior capsule of the crystalline lens of the patient by matching the 3D image and coordinates to the image of the patient's eye, wherein the calculating of the center of the anterior capsule of the crystalline lens comprises the steps of: calculating a central location of a pupillary margin; calculating an iridocorneal angle; and calculating the center of the anterior capsule of the crystalline lens by matching the iridocorneal angle to the central location of the pupillary margin.