An apparatus includes an interference optical system configured to acquire a tomographic image of an eye by using interference light between return light from the eye irradiated with measurement light and reference light corresponding to the measurement light, a determination unit configured to determine, by using at least one of information about an acquisition time for acquiring the tomographic image and information about an imaging view angle of the tomographic image, a search range for searching for a position corresponding to a first tomographic image of the eye, the position being in a second tomographic image of the eye, and the second tomographic image having been acquired at a time different from a time when the first tomographic image is acquired, and a registration unit configured to perform registration of the first tomographic image and the second tomographic image by using information about the determined search range.