LIGHT TREATMENT FOR NASA SHIFTWORKERS

Intense artificial light can phase-shift circadian rhythms and improve performance, sleep, land well-being during shiftwork simulations. In real shiftworkers, however, exposure to sunlight and other time cues m ay decrease the efficacy of light treatment, and occupational and fami ly responsibilities may make it impractical. With these considerations in mind, we designed and tested light-treatment protocols for NASA pe rsonnel who worked on shifted schedules during two Space Shuttle missi ons. During the prelaunch week, treatment, subjects self-administered light of similar to 10,000 lux at times of day that phase-delay circad ian rhythms. Treatment continued during the missions and for several d ays;afterward. No treatment was administered to subjects in the contro l group. Treatment subjects reported better sleep, performance, and ph ysical and emotional well-being than control subjects and rated the tr eatment as highly effective for promoting adjustment to their work sch edules. Light treatment is both feasible and beneficial for NASA perso nnel who must work on shifted schedules during Space Shuttle missions.