I suspect you're being down voted because article is discussing the merits between 3 devices, PC's, tablets, and phones, with the conclusion that phablets are the win in the end (with some fairly feeble 'evidence'). The fact that all three affect some peoples circadian rhythm isn't overly valuable to the conversation. Form factor is the discussion, and you're talking about light sensitivity in insomniacs. Water is a solid at -30c at sea level is also true, regardless of whether people down vote me. And neither are relevant to the article or the discussion being had.