We have previously shown that exposure of the eyes to bright light but not ordinary room light can reverse winter depressive symptoms in patients with Seasonal Affective Disorder (SAD). By now it is generally accepted that light therapy is an effective treatment for SAD. Conventional light treatment has been administered by having the patient sit in front of a large light box. Although effective, these boxes require that the patient remain in one place for the duration of treatment and are difficult to transport. To obviate these problems, we have developed a head-mounted light visor, which is light, easily portable and allows the patient to be mobile while receiving treatment. To test the efficacy of the visor, we compared the effects of two different light visors, one brighter (7000 lux) and one dimmer (400 lux), in 55 SAD patients at three sites: Bethesda, Seattle and Nashua. Treatment was administered for 30-60 minutes per day for one week. Contrary to our prediction, we found the dimmer visor to be more effective than the brighter one, yielding a response rate of 56% vs. 27%. We discuss possible reasons for this paradoxical findings and outline follow-up studies needed to corroborate its validity.
