seriously? the iphone study suggest that users stop "consuming" blue light 1 hour before sleep. they don't even control for other substances like coffee or alcohol intake or medication other than "sleep disorders"... your _robust_ ipad study has 12 people...

one of the links i posted is a meta-analysis on the subject that skimmed down ~ 130 studies down to 15 because bad metodology & conclude that blue light has effect on sleep quality