Tilburg, September 8, 2026 – Blue light therapy via the Propeaq light glasses can improve sleep quality and reduce daytime sleepiness in people with Parkinson's disease. This is according to new scientific research published in the Journal of Parkinson's Disease (September 2026). During the research, blue light therapy was administered using the light therapy glasses developed by Chrono Eyewear. The results show that participants with Parkinson's disease experienced a significant improvement in sleep quality and sleep duration and a decrease in daytime sleepiness after two weeks of light therapy.
Research into the effect of blue light therapy
Sleep problems and daytime sleepiness are common non-motor symptoms in Parkinson's disease and can have a significant impact on daily functioning and quality of life. Researchers at Radboudumc, led by Prof. Dr. Bas Bloem, professor of neurological movement disorders, investigated the effects of blue light therapy via the Propeaq light glasses on sleep quality and daytime sleepiness, among other things, in people with Parkinson's disease, in a randomized controlled trial (RCT).
A total of 30 people with Parkinson's disease participated in the study. Participants followed a fixed light therapy program for 14 days. They were exposed to blue light for 60 minutes every morning and evening, which was administered via the Propeaq light glasses. The results show that blue light therapy within two weeks led to a significant improvement in sleep quality and sleep duration and a decrease in daytime sleepiness. In addition, evidence was found for positive effects on mood. The research was completed in September 2024, and the results were published in Journal of Parkinson's Disease in September 2026.
Earlier research already laid a solid foundation
The recently published research builds on earlier research into the application of blue light therapy via light glasses in people with Parkinson's. In 2019, researchers from Radboudumc, together with Chrono Eyewear, already published the results of a retrospective study in Hindawi Parkinson's Disease. In this study, 58 people with Parkinson's disease used light glasses for blue light therapy for at least one week. Of the participants, 74% reported positive effects. These included improved sleep, less daytime sleepiness, a decrease in depressive symptoms, and improvements in motor functions.
The findings from this first study partly prompted further controlled research into the application of blue light therapy in people with Parkinson's.
“Blue light therapy via light glasses is an accessible and patient-friendly intervention. The combination of improved sleep, less daytime sleepiness, and potentially beneficial effects on mood makes this a promising addition to treatment options,” says Prof. Dr. Bas Bloem.
The role of light and the sleep-wake rhythm in Parkinson's
Parkinson's disease is much more than just a motor disorder. Although symptoms such as stiffness and tremor are most visible, many patients also experience non-motor symptoms, including disturbances of the sleep-wake rhythm, sleep problems, daytime sleepiness, and mood complaints. These complaints can have a significant impact on daily functioning and quality of life.
Light plays an important role in regulating the circadian rhythm: the internal biological clock that determines, among other things, when the body is active and when it needs rest. In people with Parkinson's, this rhythm can be disturbed. Light therapy with blue light, especially in the morning and early evening, helps the body resynchronize by stimulating the natural production of melatonin. This contributes to deeper and longer sleep, more alertness during the day, and a more stable mood. The restoration of this rhythm can, therefore, make a significant, long-lasting contribution to the daily functioning and overall well-being of people with Parkinson's.
Link to research: https://pmc.ncbi.nlm.nih.gov/articles/PMC13447595/
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