Diagnosis of fibromyalgia, meeting 2016 ACR criteria.
Having nocturnal pain (NRS 0-10 worst pain ≥ 4)
Self-reported sleep difficulties (trouble falling asleep, difficulty staying asleep, waking up too early, or waking up unrefreshed) 3 or more nights per week during the past month
You may not be if
Planned intervention during the study period
Seizure disorder
Photosensitivity
Hearing or sight problems causing inability to use hBET
Cognitive problems or dementia or mental health disorders causing inability to consent
Night shift worker
Any known primary sleep disorder including obstructive sleep apnoea, narcolepsy, restless leg syndrome
