On going fight with my buddies

[Jigger]

I'm surprised someone hasn't posted a link showing how refraction (I think I'm using the right word) affects a fish's vision from under water. If I knew how I would. I've seen quite a few drawings of this refraction in fly fishing books. What happens as I understand it is when the fish looks up, there is only a small window of things the fish sees which is in a line not quite vertical from where the fish lies. So, If you are a ways away from the fish, it won't see you.

I know I didn't do a very good job of explaining this. Maybe someone could help me that knows more about this or post a link. I know this is true because I too trout fish in very clear water at times and often the fish don't see you until you move in pretty close.