However, for those who must deal with frequent sleep timing changes, one may use a special calculator to help determine the timing for exposure to light and darkness just before and during travel or shift change. If one calculates the timing wrong, one may actually make the time phase shift worse instead of better. A travel kit can consist of a calculator, a light visor and special extra dark glasses. Some use small timed doses of Melatonin to achieve the same purpose. Other uses of bright light therapy There has been research using light therapy for PMS, obesity and non-seasonal depression.
More research needs to be done.
However, it may make sense to use light therapy as an augmentation of other depression treatments or in cases in which the individual is unable to use other forms of treatment. The study on obesity was small and needs to be repeated with a larger, more carefully selected group. The obese individuals may have lost weight because their depression was better. Individuals whose PMS was worse in the winter responded better to light therapy than individuals with PMS without a seasonal variation. A recent study, published in Science showed that 13,000lux of bright light applied to the back of each subject's knees could shift their sleep-wake cycles.