A stereoimage formation apparatus includes two lens array plates, each of which includes microlenses having optical axes and peaks. The optical axes of the microlenses are parallel to one another. The optical axes of the microlenses in one of the lens array plates are aligned with the optical axes of the microlenses in the other lens array plate. The peaks of the microlenses in one of the lens array plates come in contact with or are located proximal to the peaks of the microlenses in the other lens array plate. The microlenses of each lens array plate each have a predetermined spherical aberration greater than a predetermined minimum spherical aberration.