1. An apparatus for analyzing a sectional image of an anterior eye segment which is light-sectioned by slit light and photographed, the apparatus comprising: defining means for defining a target opacity part in the sectional image based on a density distribution being between a cornea and a fundus and being in a first direction perpendicular to an optical axis of an eye to be examined; determining means for determining an area to be analyzed based on the defined opacity part; and analyzing means for analyzing an opacity condition base on the density distribution in the determined area.