A recent study evaluated the effects of one week of self-administered morning bright light therapy (BLT) on sleep, daytime sleepiness, alertness, mood, and cognitive performance among 33 healthy university students. Conducted at The Hong Kong Polytechnic University, the randomized crossover trial compared a week of morning BLT—30 minutes of exposure to a light box emitting 10,000 lux—with a week of normal light exposure without a light device.
Read More
Results indicated that participants who underwent BLT experienced decreased daytime sleepiness, particularly at noon and in the early afternoon, as confirmed by the Karolinska Sleepiness Scale. The therapy also reduced night-to-night variability in sleep duration and improved Fitbit-measured sleep efficiency, while increasing positive affect, as assessed by the Positive and Negative Affect Schedule (PANAS). Objective cognitive performance, however, remained unchanged across the study.
The study emphasized that adequate and well-timed sleep is critical for academic performance and overall well-being, highlighting that many university students struggle with irregular sleep patterns due to lifestyle factors such as late-night study sessions and screen time. The researchers noted that BLT may serve as a practical intervention to improve alertness and mood without significant cognitive enhancements.
Participants were closely monitored throughout the study, and feedback revealed that many appreciated the therapy for enhancing alertness and sleep quality, although some reported minor side effects such as eye discomfort. Overall, this study supports the potential of morning light exposure as a simple strategy to enhance daytime functioning for university students.