1. A line-of-sight detection method in an imaging system which includes a camera for photographing a face and right and left eyes and a light source for irradiating the right and left eyes with infrared rays, said line-of-sight detection method comprising: obtaining a center point of a pupil of at least one of the right and left eyes; obtaining a center point of a cornea spherical surface of said at least one of the right and left eyes; and obtaining a direction of a vector headed from said center point of said cornea spherical surface to said center point of said pupil, wherein a data based on a morphological information is used in obtaining said center point of said pupil.