1. A method for displaying a stereoscopic image, the stereoscopic image comprising a first-eye image and a second-eye image, the method comprising steps of: (a) calculating a shift of the first-eye image with respect to the second-eye image; (b) moving the first-eye image for a length of the shift; and (c) outputting the moved first-eye image and the second-eye image to display the stereoscopic image.