PURPOSE: To display an excellent stereoscopic video on a cathode-ray tube by arranging a spectroscopic means separating a video displayed on a display surface to a video beam for left eye and the video beam for right eye in front of the display surface of a beam index type cathode-ray tube.

CONSTITUTION: A distributed defractive index lens substrate 11 is attached to the surface (outer surface) of the front glass of the cathode-ray tube 1. On one surface of the gradient index lens substrate 11, many gradient index lenses in rod shape, like a 'Selfoc(R)' lens, etc., are formed. An image splitter substrate 13 as the spectroscopic means provided with a light shielding part (barrier) 12 letting no pixel beam from the cathode-ray tube 1 pass in a slit shape is arranged in front of the gradient index lens substrate 11 at a prescribed distance. Since the light shielding part 12 is formed so as to separate a pixel 3 to left and right at every one piece, the pixel L for the left eye and the pixel R for the right eye are formed surely alternately at every one pixel.