Subject: Why do goggles help you see underwater?

I understand that our vision is impeded underwater by refraction and/
or particulates, by why is it that just one centimeter of air in front 
of our eyes makes such a drastic difference in seeing through ten or 
fifteen feet of water in front of us?  When I'm out of the water 
looking in, the water refracts like crazy, but things are in focus... 
when I'm in the water without goggles, the image isn't just refracted, 
it's blurry (I'm nearsighted, but above water I have no problem seeing 
things up close, while underwater my hand in front of my face is a 
blur)... when I'm underwater with goggles, there's far less refraction 
than above water and things are pretty much crystal clear.  Why, I 
ask, WHY?!!!

Re: Why do goggles help you see underwater?