Search

Sleep disturbance and mood dysregulation are widely-experienced and costly concerns, even at the sub-clinical level. Sleep disturbance and mood dysregulation are mechanistically and diagnostically linked through circadian rhythms. Blue light has strong influence on entraining circadian rhythms, and controlling blue light has become a target of many interventions aiming to improve sleep and mood. The use of amber lenses, which selectively block blue wavelengths of light, are one such intervention. Past studies have found that amber glasses can be a helpful adjunct treatment for some severe mental illness (e.g., bipolar disorder), but research has been inconclusive about how amber glasses affect people with sub-clinical sleep and mood concerns. Using a randomized crossover design with a wide variety of objective and self-report measures, the present study examined the effect of blue-blocking amber glasses on sleep quality, latency, efficiency, and duration, as well as positive and negative affect in 15 participants over a 14-day period. Overall, our results did not support our hypothesis that amber glasses would increase sleep quality, duration, and efficiency, and decrease sleep latency, although minor but non- significant positive changes were observed on some sleep outcome variables. Our results did, however, provide strong preliminary evidence that amber glasses enhance positive mood at night, and some evidence that amber glasses decrease negative mood in the morning. This study was limited by a small sample size, large interpersonal variation, and some participant noncompliance. Future studies should work to address these limitations, as well as solve extant methodological and analytical problems surrounding objective measures of sleep.