What it is
Mechanism evidence: human
At a glance
What it is, why people use it, the evidence, and what to know before trying it.
Why people use it
- Circadian alignment
- Earlier sleep-wake timing
- Morning alertness
Evidence at a glance
Appropriately timed morning light is a well-supported circadian cue. Exact minutes cannot be universal because outdoor brightness and individual circadian timing vary; it is a timing practice, not a treatment for every sleep problem.
Confidence: strong
Practice safety
Situations where this practice may need modification or professional guidance.
Do not stare at the sun or any painfully bright source. Protect skin from burning during longer outdoor exposure. People with retinal disease, photosensitivity or medicines that increase light sensitivity should seek clinical guidance.
- Direct sun-gazing
- Known photosensitivity without clinician guidance
Forms and variants
This review does not automatically apply to:
- looking directly at the sun
- ultraviolet tanning
- 10,000-lux clinical light box
Seen in protocols
Public protocols that include Morning outdoor light. Open one to see the full context and source.