Summary
This thesis establishes that the spectral content of a light source meaningfully influences discomfort glare, with intrinsically photosensitive retinal ganglion cells (ipRGCs) playing a dominant role beyond correlated color temperature (CCT) alone. Lighting designers should be aware that higher CCT sources can increase perceived glare discomfort even when ipRGC excitation is held constant, making spectral tuning a relevant consideration for visual comfort in indoor environments.
Key Findings
- Spectral content of white light sources significantly influences discomfort glare, with ipRGC (melanopsin-containing ganglion cell) activation identified as the primary driver of this spectral effect.
- At equivalent levels of ipRGC excitation, discomfort glare increases with higher correlated color temperature, suggesting CCT has an independent secondary influence on glare perception.
- Among 7 psychophysical methods tested, 3 were retained as most suitable for glare evaluation based on repeatability, bias control, difficulty, and duration: method of constant stimuli, paired comparison, and magnitude estimation.
- Physiological measures (pupillometry, EMG, EEG, ECG) showed no significant differences between glare and non-glare conditions under typical indoor lighting levels (~20 cd/m² background, ~150,000 cd/m² glare source at 20° eccentricity), suggesting these tools are better suited to more extreme glare conditions.
- Experimental biases were found to be significant in psychophysical glare assessments and must be accounted for in protocol design and data analysis.
Categories
Eye Health & Vision: Directly investigates discomfort glare perception under indoor artificial lighting using psychophysical and physiological methods.
The Science of Light: Demonstrates the role of intrinsically photosensitive retinal ganglion cells (ipRGCs) and spectral distribution in modulating discomfort glare responses.
Author(s)
M Iodice
Publication Year
2020
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