Brightness belongs on the calendar
Instead of moralizing screens, treat brightness like any other appointment. Many people find it easier to lower overhead lights and shift leisure reading earlier than to attempt an abrupt blackout they cannot sustain during travel weeks.
Write a “dim time” you can move by fifteen minutes when caregiving or deadlines intrude. Predictability matters more than perfection: your visual system receives a recognizable slope toward rest.
If you share a household, post the dim time where roommates can see it. Negotiation happens once on paper, not repeatedly at the moment you are already tired.