A system for determining at least one selection parameter for selecting an intraocular lens to be inserted into an eye, the system comprising: an optical coherence tomography system configured to acquire OCT data of at least a portion of an at least partially empty capsular bag of the eye; a data processing system configured to determine at least one of a position parameter and a geometrical parameter of the portion of the capsular bag, depending on the OCT data; and to determine the at least one selection parameter for selecting the intraocular lens, depending on the at least one of the position parameter and the geometrical parameter; wherein the system is configured such that the determining of the selection parameter comprises performing a regression analysis, wherein the regression analysis is configured to establish a relationship between one or more input variables and one or more output variables; wherein at least one of the one or more input variables is determined depending on the position parameter and/or the geometrical parameter of the portion of the capsular bag; wherein at least one of the following conditions (a) and (b) apply: (a) the one or more output variables comprise an optical power of the intraocular lens, a range of optical powers of the intraocular lens, a geometrical parameter of an optical element of the intraocular lens and/or a geometrical parameter of a haptics of the intraocular lens; and (b) the one or more input variables comprise one or a combination of a refractive power of a cornea of the eye, one or more radii of curvature of the cornea, and a central cornea thickness of the cornea. an optical coherence tomography system configured to acquire OCT data of at least a portion of an at least partially empty capsular bag of the eye; a data processing system configured to determine at least one of a position parameter and a geometrical parameter of the portion of the capsular bag, depending on the OCT data; and to determine the at least one selection parameter for selecting the intraocular lens, depending on the at least one of the position parameter and the geometrical parameter; determine at least one of a position parameter and a geometrical parameter of the portion of the capsular bag, depending on the OCT data; and to determine the at least one selection parameter for selecting the intraocular lens, depending on the at least one of the position parameter and the geometrical parameter; wherein the system is configured such that the determining of the selection parameter comprises performing a regression analysis, wherein the regression analysis is configured to establish a relationship between one or more input variables and one or more output variables; wherein at least one of the one or more input variables is determined depending on the position parameter and/or the geometrical parameter of the portion of the capsular bag; wherein at least one of the following conditions (a) and (b) apply: (a) the one or more output variables comprise an optical power of the intraocular lens, a range of optical powers of the intraocular lens, a geometrical parameter of an optical element of the intraocular lens and/or a geometrical parameter of a haptics of the intraocular lens; and (b) the one or more input variables comprise one or a combination of a refractive power of a cornea of the eye, one or more radii of curvature of the cornea, and a central cornea thickness of the cornea. (a) the one or more output variables comprise an optical power of the intraocular lens, a range of optical powers of the intraocular lens, a geometrical parameter of an optical element of the intraocular lens and/or a geometrical parameter of a haptics of the intraocular lens; and (b) the one or more input variables comprise one or a combination of a refractive power of a cornea of the eye, one or more radii of curvature of the cornea, and a central cornea thickness of the cornea.