High dynamic range displays and the "blue light hazard".

James A. Ferwerda¹, Aries Arditi^2
1Program of Computer Graphics, Cornell University
²Arlene R. Gordon Research Institute, Lighthouse International

Recent advances in electronic display technologies have led to the development of high dynamic range (HDR) displays that can produce a much wider luminance range than conventional devices [Seetzen04]. Peak luminances on the order of 8500 cd/m2 and contrasts approaching 30,000:1 are possible. HDR displays have the potential to revolutionize both basic and clinical vision research because they allow controlled presentation of images that accurately reproduce the wide variations in luminance we experience in the real world. HDR displays hold particular promise for low vision testing, since many impairments are exacerbated by extreme lighting conditions. However one concern about using HDR displays, is recent evidence that exposure to short-wavelength light, even at moderate levels, can cause irreversible damage to the eyes of people with retinal disease (the "blue light hazard") [Glickman02, Cideciyan05]. To assess the potential phototoxicity of HDR displays we have conducted a radiometric analysis of a prototype display made by Sunnybrook Technologies that consists of an LCD panel transilluminated by an array of high intensity LEDs. We have determined the display's spectral radiance and evaluated its output with respect to international phototoxicity guidelines [Sliney05]. While our analysis indicates that the display poses no known hazards, for additional safety we have developed an approach to reducing the display's short-wavelength output to negligible levels, while only moderately reducing its luminance. The results of this project have important implications for the use of existing HDR displays in vision research and for the design of future HDR displays.