Illuminating the future of wearable light metrology: Overview of the MeLiDos Project

Light exposure profoundly influences human health, regulating circadian rhythms and impacting wakefulness and sleepiness. Estimating the effects of light exposure under everyday conditions requires personal, wearable light logging and dosimetry approaches. This article introduces the MeLiDos Project (2023–2026), supported by the European Association of National Metrology Institutes (EURAMET). The project's first branch defines quality indices and calibration standards for wearable light loggers, adapting existing metrological standards to their smaller size and distinct purpose in the field rather than the laboratory. The second branch develops a software ecosystem, including the open-source R software package LightLogR, designed to manage the increasing volume of data, ensuring reusability, accessibility and interoperability of data. The third branch explores the potential of spatially resolved light dosimetry. The MeLiDos Project anticipates advancements in wearable light metrology, paving the way for optimizing human health and well-being through wearable light logging technologies.