Light bedrooms 'link to obesity'

I resolved this problem by sleeping with my eyes closed.

I’ve been hearing about this report, and I’m still trying to decide how they are judging their light levels.

I can’t figure out how you can see your hand but not across the room? It’s not like my hand is lit. My bedroom just isn’t big enough to make that a useful distinction. The room would have to be in total darkness for me to not be able to tell where the dresser is vs. the window or the wall.