sleep improvement

in Parkinson's disease

Parkinson research

The Radboud University Medical Center in Nijmegen conducts a lot of research into Parkinson’s disease. A phased study is currently underway into the possibilities of using blue light in Parkinson’s patients. Blue light glasses have been introduced as a possible new method to treat sleep and mood disorders in patients with Parkinson’s disease (PD). Assessing patient acceptance is an important first step towards formal testing and introduction into clinical practice. The results of the first phase were published in Parkinson’s Disease (Hindawi) Volume 2019 in June. Below you can find a summary and a link to the publication.


Light glasses with monochromatic blue light have been introduced as a possible new method of treating sleep disorders in patients with Parkinson’s disease. Assessing patient acceptance is an important step towards testing and introduction into clinical practice. 58 Patients with Parkinson’s disease use light glasses for at least a week. 74% of respondents reported subjective improvements in nighttime sleep, daytime sleepiness, depressive symptoms, motor skills or a combination thereof. All but one patient want to continue to use the light glasses, usually because they see it as a useful tool.


Portable light therapy with monochromatic blue light appears to have a positive effect on sleep, mood and motor symptoms in Parkinson’s disease. Patients generally had a positive appreciation of the light glasses as a treatment for sleep and mood disorders. A lot of research has already been done into the relationship between light, sleep and Parkinson’s disease. The studies offer hope with often special results. Light expert Toine Schoutens is involved from Chrono Eyewear BV (Propeaq) in studies into the effects of specific blue light in the bandwidth of the patented Propeaq glasses. The results of the first investigation were published in a peer-revied international journal in June 2019:

Blue Light Therapy Glasses in Parkinson’s Disease Patients’ Experience: Hindawi Parkinsons Disease:, Bastiaan Bloem PhD, Daniel van Wamelen PhD, Katarzyna Smilowska PhD from the department of Neurology, Radboud University Nijmegen (NL) and Toine Schoutens from Chrono Eyewear BV, Tilburg the Netherlands.
Volume 2019 |Article ID 1906271 | 4 pages |

The conclusions in this study are promising.

Circadian system

Parkinson’s disease is a neurodegenerative disorder characterized by the coexistence of motor and non-motor symptoms. Sleep disturbances are among the most common non-motor symptoms occurring in up to 90% of patients; these sleep disturbances reduce the quality of life and hinder daytime functioning. In Parkinson’s disease, the circadian system appears to influence motor and non-motor symptoms. For example, worsening motor symptoms (rigidity, tremor and bradykinesia) indicate abnormal circadian rhythmicity, with symptomatology worsening during the day.

Medication versus blue light

Although many different pharmacological and non-pharmacological strategies have been introduced to reduce sleep problems in Parkinson’s disease, their efficiency remains limited. Sleep medication often leads to side effects and sometimes even worsening of the symptoms. Blue light is more effective in regulating the biological clock compared to traditional polychromatic white light boxes. The light glasses used emit blue light via integrated LED light sources with a wavelength of approximately 468 nm at a light intensity of 35 – 40 Lux at 1.5 cm from the eyes (0.9 µW / cm2).



An online survey was conducted in February and March 2018 among patients who purchased the Propeaq light glasses. The study included 10 items from the System Usability Scale (SUS), supplemented with 22 questions about the effect of the glasses. In total, 39 questions were asked. The research was approved by the medical ethics review committee of the RadboudUMC.


The mean disease duration from PD diagnosis among the respondents was 6.7 ± 4.6 years. Most patients (28/31, 90%) were on medication, mainly levodopa preparations. Seven respondents (24%) used sleep medication. Most patients (23/31, 74%) used the light glasses twice a day: once in the morning and once in the evening for 30-60 minutes each time. Of the 31 patients, 23 patients (74%) reported an effect of the glasses. Of these, 16 patients (70%) reported an improvement in nighttime sleep, four (13%) an improvement in daytime sleepiness, five (16%) an improvement in depressive symptoms and four (12%) an improvement in motor skills. Five patients (16%) reported side effects; one patient reported transient calf cramps, and two other patients reported transient nausea, fatigue, headache, or dizziness.

Results research phase 1


Scientific background

Below is a list of studies on Parkinson’s disease that have a relationship with light.

  • Wenjie Sun, Junqiang Yan, Jiannan Wu, Hongxia Ma;  Efficacy and Safety of Light Therapy as a Home Treatment for Motor and Non-Motor Symptoms of Parkinson Disease: A Meta-Analysis

  • Ortuño-Lizarán I, Beach TG, Serrano GE, Walker DG, Adler CH, Cuenca N. Phosphorylated α-synuclein in the retina is a biomarker of Parkinson’s disease pathology severity.  Mov Disord. May 2018.

  • Price DL, Rockenstein E, Mante M, et al. Longitudinal live imaging of retinal α-synuclein:GFP deposits in a transgenic mouse model of Parkinson’s disease/Dementia with Lewy Bodies. Sci Rep . 2016;6:29523.
  • Meng T, Zheng ZH, Liu TT, Lin L. Contralateral Retinal Dopamine Decrease and Melatonin Increase in Progression of Hemiparkinsonium Rat. Neurochem Res. May 2012;37(5):1050-1056.
  • Witkovsky P. Dopamine and retinal function. Doc Ophthalmolu. Jan 2004;108(1):17-40.
  • Videnovic A, Klerman EB, Wang W, Marconi A, Kuhta T, Zee PC. Timed light therapy for sleep and daytime sleepiness associated with parkinson disease: a randomized clinical trial. JAMA Neurol . 2017;74(4):411-418.
  • Joyce DS, Feigl B, Kerr G, Roeder L, Zele AJ. Melanopsin-mediated pupil function is impaired in Parkinson’s disease. Scientific Reports . May 2018;8(7796):1-9.
  • Archibald NK, Clarke MP, Mosimann UP, Burn DJ. The retina in Parkinson’s disease. brain . May 2009;132(5):1128-1145.
  • Luke RJ. Measuring and using light in the melanopsin age. Trends Neurosci . January 2014;37(1):1-9.
  • Glickman G, Byrne B, Pineda C, Hauck WW, Brainard GC. Light therapy for seasonal affective disorder with blue narrow-band light-emitting diodes (LEDs). Bio Psychiatry . Mar 2006;59(6):502-7.
  • Strong RE, Marchant BK, Reimherr FW, Williams E, Soni P, Mestas R. Narrow-band blue-light treatment of seasonal affective disorder in adults and the influence of additional nonseasonal symptoms. Depress Anxiety . 2009;26(3):273-8.
  • Figuiro MG, Plitnick BA, Lok A, et al. Tailored lighting intervention improves measures of sleep, depression, and agitation in persons with Alzheimer’s disease and related dementia living in long-term care facilities. Clin Interv Aging . 2014;9:1527-1537.
  • Anderson JL, Glod CA, Dai J, Cao Y, Lockley SW. Lux vs. wavelength in light treatment of Seasonal Affective Disorder. Acta Psychiatr Scand . Sep 2009;120(3):203-12.
  • Willis GL, Turner EJ. Primary and secondary features of Parkinson’s disease improve with strategic exposure to bright light: a case series study. Chronobiol Int . 2007;24(3):521-537.
  • Kessel L, Siganos G, Jørgenen T, Larsen M. Sleep disturbances are related to decreased transmission of blue light to the retina caused by lens yellowing. sleep . Sept 2011;34(9):1215-9.
  • Willis GL, Turner EJ. Primary and secondary features of Parkinson’s disease improve with strategic exposure to bright light: a case series study. Chronobiol Int. 2007;24(3):521-537.
  • Willis GL, Moore C, Armstrong SM. A historical justification for and retrospective analysis of the systematic application of light therapy in Parkinson’s disease. Rev Neurosci. 2012;23(2):1999-226.
  • Meng, T., Zheng, ZH, Liu, TT, & Lin, L. (2012). Contralateral retinal dopamine decrease and melatonin increase in progression of hemiparkinsonium rat. Neurochemical Research, 37(5), 1050-1056.
  • Willis, G.L., Moore, C., & Armstrong, S.M. (2014). Parkinson’s disease, lights and melanocytes: looking beyond the retina. Scientific Reports, 4, 3921.
  • Willis, GL, & Armstrong, SM (1999). A therapeutic role for melatonin antagonism in experimental models of Parkinson’s disease. Physiology & Behavior, 66(5), 785-795.
  • Willis, G.L., & Robertson, A.D. (2005). Recovery from experimental Parkinson’s disease in the 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine hydrochloride treated marmoset with the melatonin analogue ML-23. Pharmacology Biochemistry and Behavior, 80(1), 9-26.
  • Videnovic A, Klerman EB, Wang W, Marconi A, Kuhta T, Zee PC. Timed Light Therapy for Sleep and Daytime Sleepiness Associated With Parkinson disease: A Randomized Clinical Trial. JAMA neurology. 2017.
  • Willis GL, Turner EJ. Primary and secondary features of Parkinson’s disease improve with strategic exposure to bright light: a case series study. Chronobiology International. 2007;24(3):521-537.
  • Willis GL, Moore C, Armstrong SM. A historical justification for and retrospective analysis of the systematic application of light therapy in Parkinson’s disease. Reviews in the neurosciences. 2012;23(2):1999-226.
  • Rutten S, Friend C, Smit JH, Berendse HW, van Someren EJW, Hoogendoorn AW, Twisk JW, van der Werf YD, van den Heuvel OA. The effects of bright light therapy on depression in patients with Parkinson’s disease and a depressive disorder[under review] †
  • Romenets, S.R., Creti, L., Fichten, C., Bailes, S., Libman, E., Pelletier, A., & Postuma, R.B. (2013). Doxepin and cognitive behavioral therapy for insomnia in patients with Parkinson’s disease–a randomized study. Parkinsonism & related disorders, 19(7), 670-675.
  • Artemenko, AR, & Levin, IAI (1996). The phototherapy of parkinsonism patients. Zhurnal nevrologii i psikhiatrii imeni SS Korsakova, 96(3), 63-66.
  • Paus S, Schmitz-Hubsch T, Wullner U, Vogel A, Klockgether T, Abele M. Bright light therapy in Parkinson’s disease: a pilot study. Mov Disord. 2007;22(10):1495-1498.
The rating of at WebwinkelKeur Reviews is 8.6/10 based on 147 reviews.