More evidence about the importance of natural sleep! Not sure about the cancer link, more evidence needed I think.
Researchers warn of the health dangers of too much light while we try to sleep. But how did our bedrooms become so bright? There are regular warnings that people aren't sleeping properly. Too much light from electronic devices before bedtime. Not enough time in bed. Excessive caffeine. Now there's another potential worry - too much light in the bedroom. Previous studies have linked light at night with ill health in rodents. Now a study of 113,000 women suggests that it could cause obesity in humans. The work by Oxford University researchers for the Institute of Cancer Research found that women had larger waistlines if their bedroom was "light enough to see across", the researchers found.