Chronic pain is a major complaint among many individuals living with hEDS and may have a severe impact on quality of life and activities of daily living. Given the complexity of the disease's pathophysiology, effective treatments are limited. A multidisciplinary approach, including pharmacologic and nonpharmacologic pain management, physical therapy, occupational therapy, and psychological treatment alongside prophylactic care and interventions has been recommended for these patients. The application of light for pain and injury has been studied for some time. More recently, specific colored light has shown promise in treating chronic pain. Green light emitting diodes significantly reduced the number of headache days in people with episodic migraine or chronic migraine. Additionally, green light emitting diodes significantly improved multiple secondary outcome measures including quality of life and intensity and duration of the headache attacks. As no adverse events were reported, green light emitting diodes may provide a treatment option for those patients who prefer non-pharmacological therapies or may be considered in complementing other treatment strategies. This investigation will examine the impacts of green light exposure on subject-reported pain severity and symptoms. Knowing whether this intervention can improve pain and quality of life in this population may offer valuable guidance to clinicians who treat hEDS patients and to hEDS patients themselves.

Subjects will be enrolled for a total of 10 weeks, inclusive of either a 10-week control white light exposure period or a 10-week experimental green light exposure period. Central sensitization inventory will be used to determine the degree of central sensitization contributing to pain for each subject at baseline.

All subjects will be provided with a light source that will achieve light intensity of 4 and 100 lux measured at approximately 1 and 2 meters from point of exposure from a lux meter to determine the illuminance and luminous emittance of the LED strips. Subjects will be free to change the distance of the light source between 1 and 2 meters from their eyes to find the intensity that best suited them. The equipment will be provided during the initial clinic visit or mailed to the patients' homes and they will be instructed to use it in a dark room with no other source of light, except provided source, for a minimum of 1 hour every day, with the option to increase the exposure time to 2 hours daily for 10 weeks. The subjects will be asked to eliminate other sources of extraneous light (no use of televisions, computers, or smartphones; curtains drawn and existing room lights turned off) and will be encouraged to keep their eyes open, to blink at a normal rate, and not to stare directly at the light source. Subjects will be encouraged to engage in any activity while undergoing light exposure, such as reading or listening to music, and avoid falling asleep. Subjects will have the option to receive a daily text message/email reminder about light exposure and questionnaire completion. They will be provided with questionnaires to document the primary and secondary outcomes. Subjects will be allowed to continue their current medical therapy as recommended by their treating physicians. They will also be allowed to start any new medications as recommended by their treating physicians and instructed to document all medications used for their pain. Subjects will self-report the light exposure log, pain medication log, and pain severity data daily to minimize the chances of recall bias. Short-Form McGill Pain Questionnaire (SFMPQ) will be self-reported by subjects every 2 weeks. Short-Form 36 Health Survey (SF-36) data will be self-reported by subjects at their initial visit, 5-week visit, and 10-week visit. Athens Insomnia Scale (AIS) and Test My Brain (TMB) cognitive performance measures will be completed at baseline and week 10. The daily log and McGill Short-Form will be completed on paper. Other measures will be set up electronically for ease of patient completion and submission, but paper evaluations will be available as a back-up if there are technological difficulties. The TMB cognitive performance tests are performed on a computerized interactive interface and patients will be given access to the activities.