A reader asks:

 From what I gather, UV light is not a necessary component to help combat the symptoms of SAD or clinical depression. Is this correct? My eye doctor proposes that patients who are prone to depression should avoid using contact lenses with UV light protection. His claim is that UV light, although damaging on many levels, helps to combat SAD. Is this in fact true? My favorite contact lenses have UV protection, and he is proposing that they may not be the best bet for me.

Answer:

Your eye doctor is simply wrong. There is no known antidepressant benefit of UV radiation in combatting SAD. The antidepressant effect occurs fully in the visible range of light wavelengths. A popular impression — thanks to unscrupulous vendors — is that “full-spectrum” fluorescent bulbs, which are designed to emit UV and a high balance of far-blue wavelengths, are somehow especially effective for treating SAD. Wrong, and we advise against using them. These bulbs are inefficient, very expensive, and produce less lux per kilowatt hour than fully effective bulbs (see our store). Don’t worry about your contact lenses, and please correct your doctor.