A three-dimensional display device, comprising: a display panel comprising an active area for display of an image mixture comprising a first image and a second image which exhibits parallax with respect to the first image; an optical element configured to define a light beam direction of image light emitted from the active area; an acquisition unit configured to acquire a position of a first eye of a user and a position of a second eye of the user, the second eye differing from the first eye; and a controller configured to drive the active area to display the image mixture based on the position of the first eye and the position of the second eye, the active area comprising a plurality of subpixels, the controller being configured to determine a first visible region within the active area, for emitting image light which propagates to the position of the first eye, determine a second visible region within the active area, for emitting image light which propagates to the position of the second eye, determine, from among the plurality of subpixels, a first subpixel intended to display the first image based on the first visible region, determine, from among the plurality of subpixels, a second subpixel intended to display the the second image based on the second visible region, drive a third subpixel intended to display the first image based on the first visible region and the second image based on the second visible region to display a third image based on a dominant eye of the user by displaying the first image as the third image when the dominant eye is the first eye and displaying the second image as the third image when the dominant eye is the second eye, wherein the optical element is a parallax barrier including a matrix with horizontal and vertical rows of a plurality of barrier regions (s) arranged in grid form, and wherein the controller is further configured to drive at least some of the subpixels to change the displayed image mixture when the position of the first eye or the second eye moves beyond a control boundary, the control boundary being defined by a repetitive pattern of lines each extending vertically by a length corresponding to the vertical length of one subpixel, and further extending vertically by a length corresponding to the vertical length of the next subpixel in the vertical direction, which is offset from the one subpixel in the horizontal direction by a distance corresponding to one subpixel. a display panel comprising an active area for display of an image mixture comprising a first image and a second image which exhibits parallax with respect to the first image; an optical element configured to define a light beam direction of image light emitted from the active area; an acquisition unit configured to acquire a position of a first eye of a user and a position of a second eye of the user, the second eye differing from the first eye; and a controller configured to drive the active area to display the image mixture based on the position of the first eye and the position of the second eye, the active area comprising a plurality of subpixels, the controller being configured to determine a first visible region within the active area, for emitting image light which propagates to the position of the first eye, determine a second visible region within the active area, for emitting image light which propagates to the position of the second eye, determine, from among the plurality of subpixels, a first subpixel intended to display the first image based on the first visible region, determine, from among the plurality of subpixels, a second subpixel intended to display the the second image based on the second visible region, drive a third subpixel intended to display the first image based on the first visible region and the second image based on the second visible region to display a third image based on a dominant eye of the user by displaying the first image as the third image when the dominant eye is the first eye and displaying the second image as the third image when the dominant eye is the second eye, wherein the optical element is a parallax barrier including a matrix with horizontal and vertical rows of a plurality of barrier regions (s) arranged in grid form, and wherein the controller is further configured to drive at least some of the subpixels to change the displayed image mixture when the position of the first eye or the second eye moves beyond a control boundary, the control boundary being defined by a repetitive pattern of lines each extending vertically by a length corresponding to the vertical length of one subpixel, and further extending vertically by a length corresponding to the vertical length of the next subpixel in the vertical direction, which is offset from the one subpixel in the horizontal direction by a distance corresponding to one subpixel.