A display apparatus comprising: a display unit configured to display a predetermined target object to be gazed at by a subject; a gaze point detection unit configured to detect a position of a gaze point of the subject who observes the display unit; a region setting unit configured to set a specific region corresponding to the predetermined target object; a determination unit configured to determine whether the gaze point is present in the specific region; an arithmetic unit configured to calculate gaze point data on the basis of a determination result of the determination unit; and a display control unit configured to, if the gaze point data meets a predetermined index display condition, display an index at a position corresponding to a gaze point of the subject on the display unit in a period in which the gaze point detection unit is detecting a position of a gaze point of the subject, wherein the gaze point data includes a first presence time in which the gaze point is successively present in the specific region, the predetermined index display condition includes a first index display condition, and the first index display condition is that if the first presence time is equal to or larger than a predetermined time, a moving index is displayed as the index at a position corresponding to the gaze point on the display unit every time the position of the gaze point is detected, wherein the gaze point data includes a second presence time in which the gaze point is successively present in the specific region, the predetermined index display condition includes a second index display condition, and the second index display condition is that if the second presence time is equal to or larger than a predetermined time, a fixed index is displayed as the index at a position corresponding to the gaze point on the display unit at the time the gaze point data meets the second index display condition, wherein the second index display condition is that the fixed index is displayed when the second presence time is equal to or larger than a predetermined time after the moving index is displayed under the first index display condition, wherein after the moving index is displayed, if the gaze point of the subject is detected outside the specific region, then the display control unit is configured to stop displaying the moving index and is configured to continue displaying the fixed index independently from the movement of the gaze point of the subject. a display unit configured to display a predetermined target object to be gazed at by a subject; a gaze point detection unit configured to detect a position of a gaze point of the subject who observes the display unit; a region setting unit configured to set a specific region corresponding to the predetermined target object; a determination unit configured to determine whether the gaze point is present in the specific region; an arithmetic unit configured to calculate gaze point data on the basis of a determination result of the determination unit; and a display control unit configured to, if the gaze point data meets a predetermined index display condition, display an index at a position corresponding to a gaze point of the subject on the display unit in a period in which the gaze point detection unit is detecting a position of a gaze point of the subject, wherein the gaze point data includes a first presence time in which the gaze point is successively present in the specific region, the predetermined index display condition includes a first index display condition, and the first index display condition is that if the first presence time is equal to or larger than a predetermined time, a moving index is displayed as the index at a position corresponding to the gaze point on the display unit every time the position of the gaze point is detected, wherein the gaze point data includes a second presence time in which the gaze point is successively present in the specific region, the predetermined index display condition includes a second index display condition, and the second index display condition is that if the second presence time is equal to or larger than a predetermined time, a fixed index is displayed as the index at a position corresponding to the gaze point on the display unit at the time the gaze point data meets the second index display condition, wherein the second index display condition is that the fixed index is displayed when the second presence time is equal to or larger than a predetermined time after the moving index is displayed under the first index display condition, wherein after the moving index is displayed, if the gaze point of the subject is detected outside the specific region, then the display control unit is configured to stop displaying the moving index and is configured to continue displaying the fixed index independently from the movement of the gaze point of the subject.