Data: Associations between light exposure and sleep timing and sleepiness while awake in a sample of UK adults in everyday life

Raw data of the research paper, 'Associations between light exposure and sleep timing and sleepiness while awake in a sample of UK adults in everyday life'. We incorporate an open-source wearable wrist-worn light logger (Spectrawear) and smart-phone based online data collection. We simultaneously record longitudinal light exposure (in equivalent daylight illuminance (EDI)), sleep timing, and subjective alertness over seven days, in a convenience sample of 59 UK adults without externally imposed circadian challenge (e.g. shift-work or jetlag). The monitor was set with a 30-second sampling interval. Participants were asked to wear the device during the day and to take it off just before their bedtimes by leaving it to a location in the same room (preferably near eye level). The repeated measure of sleepiness was collected by the Karolinska Sleepiness Scale (KSS) 10-item version (score 10: extremely sleepy). The sleep diary file includes wake time in the survey date and bedtime (zero=midnight), subjective sleep quality, sleep duration (hours), sleep latency (hours, how long it took to fall asleep after going to bed), napping, smoking, alcohol and caffeine usage yesterday. The baseline file includes age, sex, subjective health score, subjective chronotype, MCTQ MSFsc, PSQI total score, IPAQ activity category, general smoking, alcohol and caffeine usage behaviours.