What Is Bright Light Therapy?
A 10,000-lux light box used in the morning for seasonal affective disorder and circadian timing. This is about lux and clock time, not red/NIR photobiomodulation. UV should be filtered. Bipolar mania is a stop sign.
Overview
Bright light therapy is a morning dose of high illuminance—classically about 10,000 lux at the eye, UV-filtered, for ~20–30 minutes—to shift circadian timing and treat seasonal affective disorder (SAD). It is not a red LED panel, not PBM, and not a tanning bed. Clinics sometimes park a box in the lounge and call it “light therapy” next to a TheraLight bed. Those are different prescriptions.
What the evidence is for
Meta-analyses support bright light for seasonal depression; nonseasonal depression data are more mixed but not empty. Timing matters: morning is the usual antidepressant protocol. Evening bright light can delay sleep. Devices should specify lux at a stated distance. A dim “happy lamp” across the room is not 10,000 lux at your cornea.
Limits
People with bipolar disorder can switch into mania. Eye disease and photosensitizing drugs need a clinician. This will not fix an unlit night-shift life by itself, and it is not a first-line substitute for severe major depression care. Red light at night is a separate, weaker “don’t blast blue” conversation—not this protocol.
Benefits
Stronger evidence base for SAD than spa PBM has for ‘optimization’
Home devices exist; you do not always need a membership
Non-UV when the box is built for therapy
Morning ritual is the dose—clock time is the point
Cheap compared with a full-body LED bed if SAD is the job
The Procedure
1
Confirm the indication
2
Screen bipolar and eyes
3
Set distance and time
4
Do not stare into the lamp
Preparation
Use in the morning after waking. Sit at the rated distance. Skip if you are sleep-deprived from last night’s bright screens and think one box cancels that.
Recovery & Aftercare
Headache, nausea, or feeling wired: shorten the session or move the box. Agitation or reduced need for sleep: stop and get psychiatric advice.
Risks & Considerations
Mania/hypomania, headache, eye strain, insomnia if used late, and UV exposure from the wrong lamp (tanning or unfiltered).
Frequently Asked Questions
References
[1]
Golden R.N. et al. The efficacy of light therapy in the treatment of mood disorders (Am J Psychiatry, 2005).
https://doi.org/10.1176/appi.ajp.162.4.656[2]
Nussbaumer-Streit B. et al. Light therapy for preventing seasonal affective disorder (Cochrane, 2019).
https://doi.org/10.1002/14651858.CD011050.pub2[3]
NIMH. Seasonal affective disorder.
https://www.nimh.nih.gov/health/publications/seasonal-affective-disorder[4]
FDA. Radiation-emitting products.
https://www.fda.gov/radiation-emitting-products
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