Every angler knows the frustration of lining a fish. After finding that big fish actively feeding, we make a cast where we think it should be, & — quick as a flash — it’s gone. What you forgot about was the law of refraction. That fish wasn't quite where you thought it would be. You thought it was six inches below the surface. But how deep was it, — one foot, two feet, — or was it deeper? How large was it’s “circle of vision”, & does it matter? Sound confusing, well it’s surprisingly easy once you understand what is happening. Refraction has an impact on how we view a trout & its world, & conversely how a trout views us & our world. Do trout really have blind spots? How low must you be before they are aware of your presence? Does it matter what you wear & how you move? You’d be surprised at the little things that will put a trout down. We’ll watch through a trout’s eyes how mayflies & tricos float into the trout’s window — & see what the trout sees first. We’ll see that “imprint”, & the “sparkle” that you only read about. Most important of all, we will also see that “magnification of the fly” that takes place as the fly enters the trout’s window – something you may have never read about. Why are comparaduns & parachute flies so effective — does the reflected double image of a streamer, a wet fly, or an emerger cause a trout to miss? How well can trout see both above & beneath the surface? In this third installment of The Underwater World of Trout, we explore why what you see isn’t what the trout sees. More importantly, you’ll learn to interpret what you actually see to better understand what really is happening under the water.