The system (2) has an image forming apparatus comprising a display (14) for generating test patterns. An optical component is arranged in an optical path (22) of the eyes (12a, 12b) of a subject facing side (26) of the display. The optical component comprises a prism array that is extended in vertical direction comprising prism portions. The display faces in a cylindrical lens-shaped portion with a convex surface. The optical assembly includes a panel system acting as a parallax barrier, in which light of two light groups is selected from separated zones of the display. Independent claims are also included for the following: (1) an investigation device (2) a method for examining angle defective visions of the eyes of a subject.