[typon]

I read that being in the sun when you're a child and your eyes having to adjust with the change in brightness helps with reducing myopia

[mumblemumble]

The other hypothesis I've heard is that it's switching back and forth between focusing on close-up things and distant things. Which you naturally do a lot when engaging in outdoor activities, but basically not at all when staring at books or screens.

[amelius]

Perhaps a good reason to buy a HDR monitor then :)