A reader asks:

 If one is sensitive to some fluorescent light — for example, I get migraines — can light boxes be used to treat SAD?


Adverse reactions to fluorescent lighting is usually due to poorly designed lighting installations with a high glare factor, or electronic ballasting of low, 60-Hz frequency. Most likely, you would not experience such headaches using a well-designed light box with a smooth diffusion screen and high-frequency ballasting. Headache (though not migraines) is fairly frequently reported as a side effect during the first few days of light therapy, but the problem usually resolves quickly. If not, reducing light dose — for example, with shorter treatment sessions — often provides relief. Extremely few users have experienced long-term, intractable headache under light therapy.