The present invention is directed a switchable 3D/2D optical imagining system having high functional flexibility in a number of aspects and adaptability to various applications. The present invention is based on generating directional optional beams, transforming these optical beams and projecting transformed optical beams in a field of view to thereby divide the field of view into one or more adjustable viewing zones and to form 2-dimensional (2D) images or perspective views of a 3-dimensional (3D) image of an object or scene herein. The present invention is embodied in the switchable optical imaging system and 3D/2D image switchable apparatus using the same system.