Does Veiling Glare in the Human Eye Hinder Detection in High-Dynamic-Range Displays?

Ever since Stiles and Holladay (1929), veiling glare (VG) in the human visual system has been known to hinder the visibility of subtle targets. In this work, we quantitatively study how veiling glare affects contrast detection tasks using a dual-layer high-dynamic-range (HDR) display and empirically model the VG effect on thresholds. We used a binary decision for the presence of a Gaussian target in the center of the display on white noise backgrounds. The VG source was realized using a ring pattern with varying parameters. Detection thresholds were estimated using a double-random staircase technique including signal absent trials. In addition, divergence of the subject's fixation from the target in the center was tracked in real-time and used to provide auditory feedback to minimize adaptation effects. Our results are interpreted in terms of illuminance and angular distance between source and target. Sensitivity was lower for smaller angular distances and for larger source intensities. Results from three subjects were used to formulate a bivariate model of VG effect for contrast thresholds similar to Stiles and Holladay. The model can be used to suggest optimal, content-dependent, HDR presentation modes for medical images.