We cannot live without light, because we need it to work and we need it to help us get vitamin D to protect us from cancer and to build our bones. But it does not mean, that we can use light more, than nature allows us. We know, that too much sun light can cause skin cancer. But what is too much?

It turned out that even a small exposure to light during night time can cost us life! According to the recent study from Haifa University the rate of breast and prostate cancer were directly related to the artificial light at night. And there is an explanation of this finding: light at night resets out body to the day mode, shutting down the production of night hormone melatonin — one of the major factors of anticancer defense.

So how to use day light safely to improve your health, not to destroy it?
Try to get daily daylight exposure, but not too much to avoid skin damage and hence skin cancer.
Go to sleep with sun dawn and get up with sunrise.
Make sure, that there is no artificial light in your bedroom at night: no computer lights, no TV lights, no clock, no light coming from the window etc.
Even if you get up at night, do not turn the light on to try to read or do something else, because your body will think, that it is time to get up and reset your brain to the day mode.
It is not a rocket science! Give your body what it needs and you will get better.
Links:
http://74.125.47.132/search?q=cache:Tt6XaHFJpKwJ:actveng.haifa.ac.il/PDF/tehuda/eng/newsletter_2.09.pdf+israel+haifa+university+breast+cancer+satellite+melatonin+kloog+haim&cd=11&hl=en&ct=clnk&gl=us