Provided are wafer scale lenses having a diffraction surface as well as a refractive surface, and an optical system having the same. The wafer scale lens includes a lens substrate, a first lens element formed on the object side of the lens substrate, having a positive refractive power, a second lens element formed on the image side of the lens substrate, having a diffraction surface, and a third lens element deposited on the diffraction surface of the second lens element, having a negative refractive power. The invention allows miniaturized optical system and efficient calibration of angle of view, reducing the angle of light incident onto the diffractive surface, thereby increasing diffraction efficiency and eliminating high order diffraction light to improve picture quality.