A new study has found that exposure to blue-enriched light in the morning can significantly improve sleep patterns and daily activity in older adults, but using the same light in the evening may have the opposite effect. The findings, published in the journal GeoScience, suggest that carefully timed light exposure could be an effective strategy for improving sleep quality in this age group.
Researchers at the University of Surrey conducted an 11-week study on 36 adults aged sixty and above to assess how different lighting conditions affected their sleep and activity. Participants were exposed to two types of light, a blue-enriched white light and a standard white light, at different intensities for two hours in the morning and two hours in the evening. They wore wrist actigraphs and used light sensors to measure their rest activity rhythms while also keeping sleep diaries.
The results showed that exposure to blue-enriched light in the morning improved stability in daily activity patterns and reduced sleep fragmentation. Participants who spent more time in bright light above two thousand five hundred lux during the day had stronger activity rhythms, higher daytime energy levels, and an earlier bedtime. But those who received blue-enriched light in the evening experienced longer sleep latency and poorer sleep efficiency, suggesting that evening exposure disrupted their natural sleep cycle.
Age-related changes in the eye make it harder for older adults to receive sufficient natural light, which can affect their sleep and wake cycles. The study highlights how self-administered light therapy could be a promising solution, but timing is crucial to its effectiveness. Morning exposure to bright light appears to help reinforce the body’s internal clock, while late-day exposure to blue light may interfere with sleep quality.
While previous research has explored the effects of light therapy in care homes and institutional settings, this study provides evidence that similar benefits can be achieved in real-world home environments. The findings support the idea that simple changes in daily light exposure could help older adults manage sleep disturbances without medication.
Further research is needed to explore how different durations and intensities of light affect individuals with varying sleep patterns. The study also raises questions about whether customised light schedules could be developed to help older adults improve their sleep while maintaining a healthy daily routine.
