I've skimmed lots of studies about the relationship between light and health in the past. In both humans and other animals, our internal sleep-wake clocks are

I've skimmed lots of studies about the relationship between light and health in the past. In both humans and other animals, our internal sleep-wake clocks are synchronized to the day-night cycle through light exposure(and indeed, without it aren't even 24h-long), and have broad implications for mood, wakefulness, metabolism, and general health. I well might have seen something about cardiovascular problems specifically, though I don't remember.