Clear-sighted, that's me

I am, as you know, very keen on birds. I feed em, I nestbox em, I watch em, I listen to em. And I am really quite good at all those activities, well, except for the last two. Visual and aural acuity were never my strong points.
I was once showing someone round our bird sanctuary when I heard a squeaky kind of sound. "I recognise that bird call," I said, "but can't quite place it." Then I placed it: it was the sound of two branches rubbing together in the light afternoon breeze.
I was once with my old mucker, Martin, and we were looking for Egyptian Geese. "Found one!" I shouted, looking through the trees and across a meadow. It turned out to be the remains of a gnarled branch that had snapped off an oak tree.
Nothing I can do about the dodgy hearing now, even if I remove all the hairs and wax. But I think I have found a solution for the failing eyesight problem:


All I need now is a faithful native bearer to carry them round for me.