Light Therapy
Beyond seasonal affective disorder (SAD), what are the evidence-based applications of light therapy? A (Dermatologist): Phototherapy is standard for psoriasis, eczema, and vitiligo. Narrowband UVB (311 nm) is highly effective and safer than PUVA (psoralen + UVA). For acne, blue light (415 nm) kills Cutibacterium acnes by activating endogenous porphyrins. Red light (630-660 nm) is used for wound healing and anti-aging (collagen stimulation).
B (Neurologist): In neurology, bright white light therapy (10,000 lux) in the morning is first-line for SAD and is also effective for non-seasonal depression, circadian rhythm disorders (e.g., delayed sleep phase syndrome), and even Parkinson's disease-related sleep disturbances.
C (Ophthalmologist): Caution: Not all light is safe. High-intensity blue light can cause retinal phototoxicity over years. Low-level red light therapy for myopia control in children (emerging evidence) uses specific wavelengths and very low irradiance to avoid damage. Patients should never stare into an unshielded UVB lamp.
D (Consumer -…