luox: novel open-access and open-source web platform for calculating and sharing physiologically relevant quantities for light and lighting

Abstract

Light exposure has a profound impact on human physiology and behaviour. For example, light exposure at the wrong time can disrupt our circadian rhythms and acutely suppress the production of melatonin. In turn, appropriately timed light exposure can support circadian photoentrainment. Beginning with the discovery that melatonin production is acutely suppressed by bright light more than 40 years ago, understanding which aspects of light drive the 'non-visual' responses to light remains a highly active research area, with an important translational dimension and implications for "human-centric" or physiologically inspired architectural lighting design. In 2018, the International Commission on Illumination (CIE) standardised the spectral sensitivities for predicting the non-visual effects of a given spectrum of light with respect to the activation of the five photoreceptor classes in the human retina: the L, M and S cones, the rods, and the melanopsin-containing intrinsically photosensitive retinal ganglion cells (ipRGCs). Here, we described a novel, lean, user-friendly, open-access and open-source platform for calculating quantities related to light. The platform, called luox, enables researchers and research users in chronobiology, sleep research and adjacent field to turn spectral measurements into reportable quantities. The luox code base, released under the GPL-3.0 License, is modular and therefore extendable to other spectrum-derived quantities.

Effects of calibrated blue–yellow changes in light on the human circadian clock

“… Measures were taken at a distance of 68 cm from the screen at a height of 118 cm, that is, from the observer’s point of view. Values were calculated using the luox app 97 , 98 . cd = candela, SI-unit for luminous intensity.…”

Duration invariance and intensity dependence of the human circadian system phase shifting response to brief light flashes

“…The spectrum of the light measured in the corneal plane corresponded to a warmish white light (CIE 1931xy chromaticity: [0.4092, 0.3969]; CCT: 3466 K). The spectrum is visualized in electronic supplementary material, figures S1 and S2, and can be viewed on the luox [ 60 ] platform. Metrics related to the recent CIE S026/E:2018 [ 61 ] standard are given in table 1 for unit illuminance (1 lux).…”

How Smart Is It to Go to Bed with the Phone? The Impact of Short-Wavelength Light and Affective States on Sleep and Circadian Rhythms

“…The light conditions were counterbalanced across the three experimental nights. Light characteristics were calculated using luox [76], a validated web-based open-source platform for spectral calculations [77]. Light characteristics differed between the smartphone conditions in the following way: the display showed a melanopic radiance of 286.77 mW × m −2 × sr in the "no filter" condition and a melanopic radiance of 114.20 mW × m −2 × sr in the "filter" condition.…”