An image display apparatus includes an image forming device, a collimating optical system, and an optical device. The optical device includes a light guide plate, a first deflecting member that deflects light incident on the light guide plate, and a second deflecting member that deflects the light, which propagates in the light guide plate by total reflection, a plurality of times. The first and second deflecting members are provided in the light guide plate. Light having one wavelength emitted from at least one pixel satisfies the following condition: 2t·sin θ−2≦WY≦2t·sin θ+2 where an axial direction of the light guide plate is the Y-direction, WY prepresents the width in the Y-direction of the light incident on the light guide plate, t represents the thickness of the light guide plate, and θ represents the total reflection angle.