I mean the problem with many of the studies quoted and referred to in the article is that they are about correlation but fail to show causation outside of "tha

I mean the problem with many of the studies quoted and referred to in the article is that they are about correlation but fail to show causation outside of "that seems right if you approach it with a mind which has already been biased to believe it". For example night work independent of light has _a lot_ of ways it can negatively affect people, cause stress and in turn increase the risk of cancer. And while the relationship between melatonin and blue light does exist the magnitude of it's effect (compared to other factors) is much less clear and might vary hugely between people. Especially when it comes to reasons why you sleep is bad there are docents non melatonin related problems of which the negative effect can by far outweigh any melatonin difference caused by blue light.