Do High Dynamic Range Displays Pose a Hazard to the Eyes?

Abstract

Purpose: : Recently, a new class of high dynamic range (HDR) displays has been developed that is capable of presenting high resolution, full color, moving images at luminance levels that span a significant portion of the natural range, with dynamic ranges on the order of 30,000:1 and maximum luminances on the order of 8,500 cd/m². Because HDR displays can be used to study visual performance under luminance conditions more similar to those encountered in real life than presently available display technologies, they seem destined for eventual use in both basic and clinical psychophysics. HDR displays hold particular promise for low vision testing, since many functional impairments are exacerbated by extreme lighting conditions. However, recent studies have focused attention on the potentially harmful effects of ultraviolet and short–wave visible radiation, even at levels commonly encountered in clinical use, on disease–compromised eyes. This has prompted the International Commission on Non–Ionizing Radiation Protection (ICNIRP) this year to issue new, adjusted recommendations.

Methods: : We analyzed the radiometry of a prototype HDR display made by Sunnybrook Technologies, which uses a hybrid design composed of two stages: a high intensity white light–emitting diode (LED) backplane image, and a liquid crystal display (LCD) image that modulates the LED image behind it. We then compared the spectrum of the radiation emitted by the full display with radiation from natural daylight exposure and exposure limits recommended by the ICNIRP, to evaluate the display's potential to produce phototoxic effects on the eyes.

Results: : We found that of the five types of phototoxic effects identified by the ICNIRP (thermal damage to cornea, lens and retina, and photochemical damage from UV and blue–light), photochemical damage from blue–light is the only type in which there are non–negligible effects of radiation. Furthermore, we found that potentially hazardous blue–light radiation of HDR displays are well below limits established by the ICNIRP for phakic subjects.

Conclusions: : We conclude that based on present ICNIRP recommendations HDR displays are safe for viewing by subjects with natural lenses. Aphakic subjects with older non–UV filtering intraocular lens implants may be fitted with appropriate protective absorptive lenses both for viewing HDR displays and the natural environment.

Keywords: radiation damage: light/UV • aging: visual performance • low vision