Lens based on human visual system, video see-through apparatus employing the lens, and method of designing the lens

A head-mounted display (HMD) apparatus comprising:

• at least one camera configured to obtain an image by capturing a scene;
• at least one display configured to display the image obtained by the at least one camera;
• and
• a lens comprising a plurality of lens elements arranged between an eye of a user and the at least one display,
• wherein the lens includes an aperture stop area configured to be at least a portion of an area for facing the eye of the user,
• wherein the aperture stop area includes a plurality of sub-stop areas corresponding to a plurality of gaze directions by eye rotation, respectively, and
• wherein modulation values of the lens at sub-fields of 0 degrees of sub-stop areas, from the plurality of sub-stop areas, corresponding to gaze directions of 0, 10, and 20 degrees are greater than 0.7, and
• wherein the modulation values of the lens are measured at a spatial frequency between 15 to 20 cycles/mm.