An image sensor includes two or more phase-difference detection pixels disposed adjacent to each other, a plurality of general pixels spaced apart from the phase-difference detection pixels, first and second peripheral pixels, and first to third light shields. The first and second peripheral pixels are adjacent to the phase-difference detection pixels, and between the phase-difference detection pixels and the general pixels. The first light shield is disposed in one of the general pixels and has a first width. The second light shield extends into the first peripheral pixel from a first area between the phase-difference detection pixels and the first peripheral pixel, and has a second width different from the first width. The third light shield extends into the second peripheral pixel from a second area between the phase-difference detection pixels and the second peripheral pixel, and has a third width different from the first width.