IRIS is a patent-pending, circadian illumination system designed to operate within an illusory skylight. IRIS uses a virtual portal to the sky whose perceived depth reproduces daylight’s spatial canvas. Using intertwined algorithms, interiors gain the therapeutic benefits of dynamic daylight. PRiSM (Proprietary index of Spectrum Modulations) is composed of seven weighted wavelengths that mimic the sunrise-to-sunset arc with the most subtle hue and saturation gradients, lending the sky view an ethereal and translucent quality. DiAL (Daylight intensity Algorithm) mimics the organic illumination variability inherent in daylight when clouds drift beneath the sun. Together these functions support our circadian and ultradian rhythm governing attention and mental acuity.