Relationships between light exposure and aspects of cognitive function in everyday life

This study aimed to investigate the impact of real-world light exposure on cognitive performance, revealing both immediate and cumulative benefits. To achieve this, we employed a wearable melanopic equivalent daylight illuminance monitor (Spectrawear) alongside a mobile application (Brightertime) to assess subjective sleepiness, vigilance, working memory, and visual search performance throughout the day in everyday life.

The wrist-worn light dosimeter recorded continuous light exposure at 30-second intervals over a one-week period. The mobile app facilitated data collection, including baseline sociodemographic and health questionnaires, chronotype and sleep quality assessments, daily sleep diaries, and subjective sleepiness reports and cognitive task performance measurements. Participants could engage in cognitive assessments multiple times per day at their convenience.