An image sensor includes a plurality of pixels configured to receive an optical signal incident through a first lens portion; a planarization layer that has a same refractive index as a refractive index of the first lens portion; a second lens portion that is configured to classify the optical signal incident through the first lens portion according to an incidence angle, and is configured to deliver the optical signal to each of the plurality of pixels; and image processing circuitry configured to generate a subject image by combining one or more subimages obtained from the optical signal, wherein the planarization layer is arranged between the second lens portion and the plurality of pixels.