Disclosed are a display apparatus and a method of controlling the same. a display apparatus including: a display; an optical sensor; and a processor configured to: identify an operation cycle shorter than an idle section of an infrared (IR) signal and including at least a part of a section for a detection operation of the optical sensor, based on the IR signal of which a signal section corresponding to a user key input and the idle section are repeated on a predetermined cycle, control the optical sensor to repetitively perform the detection operation on the identified operation cycle, and perform a predetermined operation based on a detection value obtained by the detection operation of the optical sensor.