April 11 is World Parkinson’s Day, and during this month events are taking place around the world to raise awareness and vital funds for research into better treatments and ultimately a cure.

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 | https://doi.org/10.1155/2019/1906271

The conclusions in this study are promising.


Light expert and Founder of Propeaq



Background. Blue light glasses have been introduced as a possible new treatment option to treat sleep disturbances in patients with Parkinson disease (PD). Assessing patient attitudes represents a key step in the road towards formal testing and introduction into clinical practice. Specifically, we aimed to assess how patients experience the use of blue light glasses, aiming to optimise compliance in upcoming clinical trials where these glasses will be tested for efficacy. Methods. We invited 58 PD patients who had used the blue light glasses for at least one week on a daily basis to complete an online survey about their experiences and self-reported impact. For this purpose, the System Usability Scale was used, supplemented with additional questions about (side)effects. A total of 31 patients (53%) replied. Results. 74% of respondents reported subjective improvements in night-time sleep, daytime sleepiness, depressive symptoms, motor functioning, or a combination thereof. The median score for the System Usability Scale (SUS; 0–100 range, higher scores indicating better performance) was 70.0. A total of 26 patients (84%) had an overall positive attitude towards the technique, with patients rating the glasses with an average score of 6.9 ± 2.0 (SD) out of 10. Except for one patient, all responders would like to continue using the glasses, mostly because they considered it a useful aid. Conclusion. Blue light therapy appears to have a positive effect on sleep, mood, and motor symptoms in PD. PD patients had an overall positive attitude towards blue light glasses as treatment for sleep disorders.

A phase II randomized, placebo-controlled trial is currently underway, with results expected in the coming months. We will be sharing these results as soon as the study is published.


Light is the most potent environmental cue regulating majority of behavioural and physiological functions (LeGates et al., 2014). Accordingly, light therapy has been widely applied to improve several disorders including circadian misalignment, depression, sleep disorders and cognitive dysfunction (Schroeder and Colwell, 2013; LeGates et al., 2014). All these disturbances may co-exist with PD syndrome (Chaudhuri et al., 2006; Chaudhuri and Schapira, 2009) and are therefore expected to benefit from appropriate light regimes.
Potential insights from the use of light therapy in animal models of PD are discussed in Box 2. In the PD population, six studies so far have assessed the safety and therapeutic efficacy of light therapy (Willis and Turner, 2007; Paus et al., 2007; Willis et al., 2012; Rios Romenets et al., 2013;Videnovic et al., 2017; Martino et al., 2018).

In 2007, two studies were published (Willis and Turner, 2007; Paus et al., 2007). Willis et al. exposed 12 PD patients to 1–1.5 h of bright light pulses of 1.000–1.500 Lux in intensity 1 h before bedtime during 1 to 5 weeks (Willis and Turner, 2007). The investigators reported significant improvement of motor function including bradykinesia and rigidity. Tremor was not improved by light therapy. Bright light therapy had an anti-depressant effect that lasted several weeks following treatment and was exteriorised by increased socialisation. Subjective self-assessment of sleep habits showed also significant improvement (Willis and Turner, 2007).

Another study by Paus et al. was a randomized, placebo-controlled and double-blind pilot clinical trial of light therapy (Paus et al., 2007). The experimental group consisting of 18 PD patients received 30 min of bright light of 7.500 lx and was compared to 18 PD patients receiving placebo light pulses of 950 lx. Light was administered 1 h after awakening daily for 2 weeks. Patients receiving bright light showed improvement in depression. With the exception of a slight attenuation of tremor, no improvements were reported in motor symptoms (i.e. bradykinesia and rigidity). Regarding the sleep-wake cycles, the function assessed was excessive daytime sleepiness that improved with light therapy in both the active and placebo group with no significant in between-group difference. Although showing promising results, the main limitation of these two studies was the short-term duration of light administration which may explain the modest treatment effects and preclude any conclusion regarding the safety and efficacy of the desirable long-term administration of light therapy to PD patients in routine clinical settings (Willis and Turner, 2007; Paus et al., 2007).

The rating of www.propeaq.com at WebwinkelKeur Reviews is 8.6/10 based on 146 reviews.