Modern life, predominantly spent indoors, has profoundly altered natural patterns of light exposure,
including the intensity, spectral composition, and timing of light that humans experience daily.
These changes are particularly relevant given the growing understanding of how light influences
not only visual processes but also numerous physiological and psychological functions like circadian
rhythms, sleep, and alertness. As modern environments increasingly disconnect individuals
from natural light cycles, it is crucial to explore how life with light can be better aligned with human
biology to promote health and wellbeing. An important tool in this effort is light-dosimetry â the measurement
of personal light exposure with wearable sensors. Light-dosimetry allows for the epidemiological
assessment of personal light exposure in real-life settings across a variety of populations,
such as different occupations, cultures, and environments, and serves as an important correlate of
non-visual responses and health outcomes. Despite its potential, light-dosimetry is still a relatively
new field and lacks standardised operating procedures, which limits the comparability of studies
and the ability to interpret research outcomes. At the same time, the accumulating evidence from
laboratory studies on the effects of light on non-visual responses increasingly demands the assessment
of these relationships in real-life settings.
To address these challenges, this thesis seeks to advance the field of light-dosimetry by addressing
methodological challenges and exploring novel approaches. It reviews important considerations
in the measurement of personal light exposure and presents various metrics for quantifying
and analysing the complex data generated by wearable light sensors. Additionally, the thesis introduces
novel approaches for capturing the spatiotemporal dynamics and spectral characteristics
of personal light exposure, offering a more nuanced understanding of lighting conditions experienced
in real-life. The practical applications of these advances are demonstrated in intervention
and observational studies, exploring how light-dosimetry can be used to assess the impact of different
lighting conditions in built environments and workplaces, and evaluate their effects on healthrelated
outcomes. By examining light exposure in real-world settings, this research highlights the
complex interaction between lighting design and individual behaviour, showing how both environmental
factors and personal habits shape light exposure patterns. It also demonstrates the utility
of light-dosimetry in linking exposure to non-visual responses and health-related outcomes, such
as in office workers or vulnerable populations like nightshift workers.
This thesis contributes to integrative lighting research by laying the groundwork for the further
development of light-dosimetry to support studies on the role of light in real-life. It provides a rationale
for the importance of accurate light measurement, proposes novel approaches for improving
the assessment of personal light exposure, and highlights the role of light-dosimetry in linking lighting
conditions with health outcomes. Through these contributions, this thesis offers an important
step forward in integrating the benefits of light into modern living, with the ultimate goal of promoting
health and wellbeing through informed, evidence-based lighting practices.