I've been a proponent of natural, bright daylight for a long time. It's why I sit right in front of a south-facing window in my home office, and I try to take a 30+ minute walk/run every day in the middle of the day, no matter the season, to maximize my sunlight exposure. I live north of the 43rd parallel and our winters have short daylight hours (although nothing like Scandinavia, Alaska, etc). I have never been diagnosed for SAD (Seasonal Affective Disorder), but I am fairly sure I, and practically everyone, have some mild form of it. Taking vitamin D in the winter helps a little, but nothing beats actually getting out in the sun. Humans just aren't meant to sit inside in the dark all day. It's amazing what sitting outside in the sun, even in negative temperatures, do for my mood and productivity.

I have enjoyed reading all of the posts on HN lately about creating brighter rooms. However instead of creating a solution with LEDs, I am determined to further increase my exposure to natural sunlight. As my wife and I get ready to buy or build a new house, I am all-in on installing skylights and as many windows as possible. Even a fully overcast day has 1000-2000 lux of brightness at midday.