Image display apparatus, image display method and glass apparatus

An image display apparatus is disclosed. An image display apparatus according to various embodiments of the present invention comprises: a signal processing unit for forming the image frames of 2-dimensional (2D) content or 3-dimensional (3D) content; an output unit operable in a first mode for displaying the image frames of 2D content outputted from the signal processing unit on a display unit or a second mode for displaying the image frames of 3D content outputted from the signal processing unit on the display unit; an interface unit for receiving a user command; and a control unit for controlling the output unit to switch the mode and output the image frames according to a mode switching command which is received through the interface unit and allows the output unit to operate in any one of the first and second modes. [Reference numerals] (120) Signal processing unit; (130) Output unit; (150) Interface unit; (160) Control unit