Exercise and liver function. Pure and simple.If you are staring in the dark or at lights your eyes aren't closed. People don't sleep with their eyes open and don't go to sleep that way either. And if you didn't do it for at least 5 weeks in a row then you didn't actually try it. It takes at least 5 weeks to form a new habit, a bit longer for some. And that's a studied and proven fact as well. In bed at 10:58-11:02 seven nights a week, up at 06:28-06:32 seven mornings a week, eyes closed every minute asleep or not, no exceptions, and after 5 weeks it will be a habit and very likely sleeping almost all of it due to it now being your physical habit. If so, much better sleep pattern and the health benefits that go with it. If not, you confirmed you're one of the strange few who don't adapt physical habits. And maybe get written up in the next study.
He needs to actually exercise, vigorously, at a time of day that suits his body type. Usually AM or mid Afternoon. "Work" can be exercise if you are a logger, a mechanic, not so much.
He needs to cut out the sugar, simple carbs, caffeine after 10AM and alcohol. I say also drink lemon water and ACV water.
Of course he will not do these things. But he has been told.