> Perhaps there's correlation between sunlight exposure and being out in "large spaces" where the majority of what you're seeing is farther away than your homes

> Perhaps there's correlation between sunlight exposure and being out in "large spaces" where the majority of what you're seeing is farther away than your homes' walls. This was one of the other leading hypotheses for a long time. More recent data came down pretty decidedly on UV light rather than focal range. See my other comment: https://news.ycombinator.com/item?id=16248851 https://news.ycombinator.com/item?id=16248851