The virtual retinal display: a new technology for virtual reality and augmented vision in medicine.

INTRODUCTION: The Virtual Retinal Display (VRD) is a new technology for creating visual images. It was developed at the Human Interface Technology Laboratory (HIT Lab) by Dr. Thomas A. Furness III. The VRD creates images by scanning low power laser light directly onto the retina. This special method results in images that are bright, high contrast and high resolution. In this paper, we describe how the VRD functions, the special consequences of its mechanism of action and potential medical applications of the VRD, including surgical displays and displays for people with low vision. A description of its safety analysis will also be included. In one set of tests we had a number of patients with partial loss of vision view images with the VRD. There were two groups of subjects: patients with macular degeneration, a degenerative disease of the retina and patients with keratoconus. Typical VRD images are on the order of 300 nanowatts. VRD images are also readily viewed superimposed on ambient room light. In our low vision test subjects, 5 out of 8 subjects with macular degeneration felt the VRD images were better and brighter than the CRT or paper images and they were able to reach the same or better level of resolution. All patients with Keratoconus were able to resolve lines of test several lines smaller with the VRD than with their own correction. Further, they all felt that the VRD images were sharper and easier to view. The VRD is a safe new display technology. The power levels recorded from the system are several orders below the power levels prescribed by the American National Standard. The VRD readily creates images that can be easily seen in ambient roomlight and it can create images that can be seen in ambient daylight. The combination of high brightness and contrast and high resolution make the VRD an ideal candidate for use in a surgical display. Further, tests show strong potential for the VRD to be a display technology for patients with low vision.