A calibrating method for calibrating the position of pictures on display elements of a binocular displaying device, the binocular displaying device comprising a right display element and a left display element to display right and left pictures. The method comprising a virtual markers displaying step, during which a right virtual marker and a left virtual marker are displayed respectively from the right display element and the left display element when the wearer uses the binocular displaying device, the right and left virtual markers being at least visually vertically alignable with a real world target at an alignment condition, and an aligning step, during which each of the right and left virtual markers are aligned with the real world target.