Green-light Lamp
Summary:
Green-light therapy involves exposure to narrow-band green light, which has been shown to reduce photophobia and migraine frequency in some individuals.
Biological Plausibility
Green light activates different photoreceptors and cortical pathways than blue or white light, potentially reducing thalamic activation linked to photophobia. Animal models suggest it modulates central pain circuits via retinal input.
Evidence
Small clinical studies suggest exposure to green light for 1–2 hours per day may reduce migraine frequency and intensity. Evidence remains preliminary but promising.
Effect Size
Reported reductions of 2–3 migraine days/month in pilot studies. Around 50% of patients report reduced light sensitivity during attacks.
⚠️ Risk
Very low. May cause mild eyestrain or sleep disruption if used late in the day.
Cost
$$
Scores
- Benefit: 3
- Burden: 3
- Ratio: 1
Clinical Takeaways
- Best suited for patients with light-triggered migraine or strong photophobia.
- Effects may require daily use over several weeks.
- Should not replace evidence-based preventive therapies, but may complement them.
Key References
- Ibrahimi M, et al. *Evaluation of green light exposure on headache in migraine patients: A preliminary study.* Cephalalgia. 2020.
- Noseda R, et al. *A neural mechanism for exacerbation of headache by light.* Nat Neurosci. 2010.