Impact of light logger and dosimeter placement on wearability and appeal in real-life settings.

Background: Light exposure plays a crucial role in human health, influencing sleep, circadian rhythms, and visual development. As wearable light loggers are increasingly used to monitor real-world light exposure, their design must balance metrological accuracy with comfort and usability. Methods: We assessed the perceived wearability and appeal of eight light logger designs and placements (chest pin, wrist, necklace, sleeve collar, collar pin, neck loop, hat pin, and glasses) using an online survey completed by 145 participants (mean age 32 years, 52% female) from the UK, USA, and other countries worldwide. Each design was rated on overall attractiveness, likelihood of wear at home, at work, in public settings, in social contexts, during exercise, expected wear duration, and perceived interference with daily activities. Results: The chest pin received the highest overall ratings, followed by wrist and necklace, while glasses and hat pin placements were rated lowest across most contexts. Likelihood of wear was highest in the home setting and significantly lower in social (β = -0.92 ± 0.08) and work (β = -0.84 ± 0.08) contexts. Compared to the chest pin, other placements were rated up to 2.6 points lower (e.g., glasses: β = -2.62 ± 0.10). Wearing position significantly influenced all ratings (p < 0.001), while sample location and gender showed minimal effects. The thematic analysis of free-text responses revealed concerns around comfort, appearance, stability, and interference with daily activities. Conclusions: These findings highlight the importance of user-centred design and offer practical guidance for wearable light loggers that are acceptable in everyday contexts.