An intermediate image of an image from the LCD module 142 is deflected by reflection mirrors M1 and M2 via zoom automatic focus control system (g) and then is formed on diffusion glass 131 via relay lens (b) and reflection mirrors M3 and M4. The LCD image is projected on the retina of eyeballs via eyepiece lens 132 by the light flux diffused at an order of .+-.20 degrees by diffusion glass 131. One side of the eyepiece lens 132 close to the crystal balls 2 has an aspherical shape of a Conic surface and a Conic coefficient of the Conic surface is -1 and less. Thereby the optical system that has a viewing angle of 60 degrees and over and has a small aberration can be obtained.