An electronic device for displaying augmented reality (AR) includes: an optical engine configured to output light of virtual image; a waveguide from which the light of the virtual image is output and through which light of a real scene is transmitted; an optical shutter configured to transmit or block the light of the real scene; a focus tunable lens configured to adjust a focal length for the light of the virtual image output from the waveguide; and one or more processors configured to, during a first period, control the optical shutter to block at least part of a first light of the real scene, and control the focus tunable lens to have a first focal length, and during a second period, control the optical shutter to transmit a second light of the real scene, and control the focus tunable lens to have a second focal length different from the first focal length.