1. A method for capturing a tomographic image of an eye, the method comprising: obtaining a plurality of tomographic images with respect to a same position of an examinee's eye, each of the plurality of tomographic images being obtained by an optical scanning in a lateral direction of the examinee's eye to obtain a plurality of A-scan signals in a depth direction of the examinee's eye and aligning the plurality of A-scan signals on a plane in the lateral direction to obtain each of the tomographic images; selecting a reference tomographic image and an object tomographic image from the plurality of tomographic images; dividing each of the reference tomographic image and the object tomographic image into a plurality of areas with respect to the lateral direction; setting reference points of the reference tomographic image and reference points of the object tomographic image, each of the reference points being set on one of the plurality of A-scan signals in each of the plurality of areas; obtaining displacements between the reference points of the reference tomographic image and the reference points of the object tomographic image; obtaining an approximation straight line or an approximation curve of the reference points of the object tomographic image, the approximation straight line or the approximation curve indicating displacements in the lateral direction and the depth direction between the reference points of the reference tomographic image and the reference points of the object tomographic image; moving each of the A-scan signals of the object tomographic image, on which the reference points are set, by the displacements in the lateral direction and the depth direction indicated by the approximation straight line or the approximation curve to correct the displacement among the tomographic images; and moving each of the A-scan signals of the object tomographic image, on which the reference points are not set, by the displacements in the lateral direction and the depth direction indicated by the approximation straight line or the approximation curve to correct the displacement among the tomographic images.