A light-guiding plate of an optical device has first light convergence portions and second light convergence portions. The light convergence portions each have optical surfaces that cause light to be emitted from an emission surface in directions in which the light substantially converges at or scatters from one convergence point or one convergence line, the convergence points or lines for the light convergence portions are different from each other, first and second images are formed by a collection of the convergence points or lines of the first and second light convergence portions, respectively, and in a case where an image is projected to a plane perpendicular to the emission surface and parallel to a light-guiding direction of the light-guiding plate, the first and second light convergence portions cause light to be emitted from the emission surface at a first angle and at a second angle, respectively.