An image sensor includes a photoelectric conversion element structured to receive incident light and convert the received light into electric charges; a plurality of transfer transistors electrically coupled to the photoelectric conversion element to respond to a transfer signal to selectively transfer the electric charges out of the photoelectric conversion element; and a lag prevention structure formed at a center of the photoelectric conversion element and structured to receive the transfer signal to operate together with the plurality of transfer transistors to facilitate transfer the electric charges out of the photoelectric conversion element.