A reader asks:

 I have a 10,000 lux light box, but find myself unable to wake up early enough to use it at the recommended time (7:00 a.m. by the Morning-Eveningness Questionnaire). A dawn stimulator is probably out because my partner works an evening shift and has to sleep late. Do you have any recommendations for helping someone to get up? Going to bed earlier would seem to be a reasonable answer but even if I go to sleep at 10 p.m. I still cannot get up at 7 a.m.

Answer:

Two basic answers: (1) Start by using your light box when you do finally get up, even if that is late. This will have the effect of making it easier to rise earlier. Every few days, advance the time of your light therapy sessions earlier by 15 minutes (or 30 minutes, if you suddenly begin waking up substantially earlier). Before long, you should be able to wake up at 7:00 a.m. without effort. (2) Out of concern for your welfare, perhaps your partner would agree to wear a sleep mask so you could gain the advantage of dawn simulation. The major reason you cannot get up earlier, no matter when you go to sleep, is that the internal circadian rhythm clock in your brain is not producing its wake-up signal until later. The essence of morning light therapy lies in resetting the internal clock earlier.