Methods for Improving Depth Perception in HMDS

Abstract : Head mounted display systems typically present imagery to the user focused either at infinity (collimated light into the eyes), or alternatively at some nominal finite distance in the order of 11-18 feet (diverging light into the eyes). When the imagery presented by an HMD is focused at a finite distance, the right and left eyes are sometimes intentionally set to converge to that same distance. Alternatively, the eyes are often left viewing parallel to one another. In some HMDs the user is permitted to select his or her own preferred focus distance. There appears to be an advantage in improving depth% perception in an HMD simulation environment by altering in real time the focus or apparent object distance to match the distance of the principal object or objects being viewed at that time by the user. An eye tracker may be employed to determine where in the scene the user is looking, and the data is fed back to the computer to perform as appropriate the refocusing task based on the known distance of the object being looked at. Further realism improvement is likely by changing the convergence as well. This paper will discuss the relative merits of altering the accommodation and convergence as well as the means for accomplishing the refocusing task in% the HMD viewing optics rapidly, in real time, and without otherwise altering the image quality or magnification. The net goal is to improve the overall realism of the simulation to the user.