Amber glasses align the circadian rhythms behind mood and sleep
STUDY: Hester L et al, Chronobiology International 2021;38(10):1375–1383
STUDY TYPE: Systematic review
FUNDING: Independent
Background
Blue-blocking (amber) glasses work by filtering out the wavelengths of light that suppress melatonin, the neurohormone that drives sleep and circadian rhythms. This review gathers the evidence — published and unpublished — for insomnia, bipolar mania, and depression.
The Study
29 studies — including 16 randomized trials with 453 patients — examined evening blue-blocking glasses for sleep or mood disorders. Studies covered insomnia, delayed sleep-phase disorder, shift work, jet lag, bipolar disorder, major depression, and postpartum depression.
Sleep
The evidence for sleep was consistent: across multiple RCTs, blue-blocking glasses helped people fall asleep earlier, increased total sleep time, improved sleep efficiency, and enhanced melatonin by advancing its onset. That makes them a good option for night owls who struggle to sleep at night or wake up in the morning. Evening light from screens and energy efficient bulbs is rich in blue light, which shuts melatonin down, but with the glasses on melatonin rises just as it would in a dark room.
Jet Lag
They also reduced jet lag in an unpublished randomized trial from Dr. Youngstrom, who rallied his colleagues to test the glasses as they flew from the US to Korea for a summer teaching program. If you use them for travel, Jet Lag Rooster is an app that guides sleep and wake times. Follow those directions and put the glasses on a 1-3 hours before sleep.
Bipolar and Depression
The bipolar mania data is smaller. In a randomized placebo controlled trials of 32 hospitalized manic patients, amber glasses improved mania within a week with a large effect size (1.86). They were worn as part of dark therapy, where patients either wear the glasses or stay in a pitch dark room from 6 pm to 8 am.
Studies in depression were mixed and inconclusive. Although nocturnal light raises the risk of depression, we can’t say that blocking it treats depression. These studies were small and one trial suffered from poor adherence to the glasses.
Practice Implications
- For patients with insomnia, recommending amber glasses 2–3 hours before bed. They are unlikely to feel tired on them, but will fall asleep more naturally and wake up more refreshed, as they improve sleep quality.
- Night owls are likely to benefit most.
- For bipolar mania, they are one of few non-medication interventions we have.
- Many commercial glasses do not block enough blue. Here are lab-tested pairs.
— Chris Aiken, MD
Director, Psych Partners
Editor in Chief, Carlat Psychiatry Report
What’s Your Take? Share in Comments
- Are you seeing benefits with blue light blockers?
- Do your patients encounter obstacles with them?
