Spatially dependent veiling glare degrades image quality in medical extended reality

Abstract

AbstractSpatially dependent veiling glare in medical extended reality (MXR) degrades image quality and needs to be characterized across technologies. Measurement methods of veiling glare on virtual and augmented reality (VR and AR) head-mounted displays (HMDs) have not been established in regulatory evaluation of MXR devices or display measurement standards. We describe an experimental bench setup enabling highly flexible translations and rotations of the light measuring device in five degrees of freedom within the eye box. Glare point spread functions (PSFs) of multiple VR and AR headsets are extracted and compared across the display field of view (FOV) in dark environment. At the center, the evaluated VR headsets (HTC VIVE Pro and VIVE Pro 2) demonstrate reduced long-range glare compared to the tested AR HMDs (Microsoft HoloLens 2 and Epson Moverio BT-300). The measured PSFs at multiple locations are spatially invariant for the HoloLens 2. However, veiling glare on the evaluated VR HMDs substantially increases toward the periphery of the FOV primarily due to optical aberration. For VR devices in medical use, increased peripheral glare can lead to image quality degradation and poor visualization of anatomical details.