Designing Metameric Light: Advanced Methods for Isolated Photoreceptor Response and Testing NIF Effects of Light

Light does not only enable the visual system to perceive the outside world but it also impacts humans via non-visual processes such as regulating the circadian system or inducing instantaneous changes in alertness and mood. To be able to understand and quantify the effects of light on humans, we need sophisticated light designs that allow us to specifically target the desired photoreceptors. Experiments testing for the effects of light on human physiological and psychological processes have the caveat of using visually distinguishable light that hampers blinding participants to the experimental conditions and disentangling visual and non-visual processes. Metameric lighting might offer a solution to this challenge. In this paper, we propose an algorithmic approach using the principles of silent substitution and formulating it as an optimization problem to help researchers calculate metameric light pairs efficiently. Keywords— metameric light, ipRGCs, non-image-forming effects, silent substitution, tunable LEDs, optimization.