I found this interesting enough, although it's hardly a surprise that spending a couple of hours a day outdoors is good for your health. Sunlight inhibits excessive eye growth, mediated by retinal dopamine.
This is particularly important for kids: you can't watch TV and play video games inside all day. You must get out or risk wearing glasses the rest of your life.
Even if you are old and your eyes are already ruined (like mine), it's still a good idea to get out daily for overall health.