Visual Discomfort Assessment in Office Environments: Light-induced Physiological Responses and Visual Performance

Zahra Hamedani, University, My, Henry Skates
2020
The benefits of exploiting natural light in office environments are numerous, ranging from enhancing human mood, satisfaction, productivity, health and wellbeing to reducing the energy consumption required for electric lighting. However, excessive sunlight remains problematic in terms of glare and undesirable visual discomfort. The existing discomfort glare predictive models are mainly derived from conventional subjective evaluations and photometric measurements and there is always a degree of
more » ... ncertainty and bias associated with subjective measurements. For this reason, a more promising research method of pairing subjective assessments with objective measures was proposed as an alternative approach. In this research, a comprehensive method is utilised to investigate a full range of potential objective measures of visual discomfort, including involuntary light-induced physiological responses, eye movements and visual performance. This method couples physiological measurements and visual performance assessments with conventional photometric measurements and subjective evaluations. For this investigation, an experimental study was carried out for three different scenarios: low, medium, and high glare probability. Participants were required to perform simulated office tasks, while an eye-tracker recorded the pupil and ocular data. The ocular and pupillary metrics extracted from these data were: mean Pupil Diameter (PD), Pupillary Unrest Index (PUI), spontaneous Blink Rate (BR), Blink Amplitude (BA), number of fixational eye movements during reading (Fixation Rate (FR)), average Fixation Duration (FD), and Eye Convergence (EC). In addition, for each participant, the Combined Visual Performance (CVP) and Combined Reading Performance (CRP) were measured during the experiment. Analyses of variance were undertaken to determine differences on all measures among three lighting conditions with low, medium and high levels of visual discomfort. The results show significant differences between the high and low discomfort group [...]
doi:10.25904/1912/1479 fatcat:qxzwwqeavvg7tgpufoig7ak5s4