I'm not sure I understand, but I want to: Do you become engaged in a project and fall asleep later because it's hard to drop the project, or do you become engaged in a project and use a bright screen and the screen causes you (through some screen-body interface mechanism) to fall asleep later?
It is unknown to me, honestly. Most of the time I am simply not tired, which I blame the screen for. When I do get tired I usually push it even later if I'm working on something good.
