There was a debate I found hugely fascinating on Radio 4 a week or so back about how and what we see as humans and how animals have eyesight patterns that have developed in different ways, necessary for the lifestyles and survival of each particular species.

Eastern Daily Press: The 13lb 8oz bream took my breath away. Picture: John BaileyThe 13lb 8oz bream took my breath away. Picture: John Bailey (Image: Archant)

It's the same, of course, in the fish world. A catfish has pinhead eyes simply because it lives in the slime and uses its feelers and sense of smell to find its food, often in the shape of a rotting carcass. A brown trout on the other hand has large, supremely-efficient eyes that enable it to pick out the endless stream of invertebrates on which it lives.

A further interesting point was made in the discussion. It appears to have been proved that women can see shades of colour more acutely than men can. This has been put down to the fact that for centuries women have been more attuned to fashion and better educated to recognise the slightest nuance of colour as a result. By contrast, if a shirt or a suit actually fits, a bloke is likely to buy it, whatever the colour.

All fine, I thought as I listened. Then it struck me how fortunate we anglers are by comparison with the normal run of colour blind chaps that don't go fishing. The other morning, sitting behind my rods on an island, in the middle of a lake, I watched the south-westerly break up the cloud and I counted 16 markedly different shades above me, through grey to pewter to sky blue. Then I caught a tench. My, what a fabulous sheen of mahoganies, walnuts, coppers and butter-yellows played along the flanks of that 7lb beauty. Add to that the coal-black tinge to the fins and the eye as scarlet as a scalded cherry and I think the fashion editor of Vogue would be stuck for superlatives. Then, to my delight, a 13½lb bream came my way. That, as we all know, is a big fish, but as I gazed on it in the net, I saw all the shades of brown that the tench had displayed with at least another half dozen tints in addition. There were shades of charcoal on the shoulders, a sovereign-gold to the eye, a creamy-white to the stomach and a burnished-gold played on the gill flaps.

A trout man can tell you a single fish might have spots of a score of different colours making it look like a crazed aquatic leopard. A salmon can be coloured everything from blood-red to a silver that is impossible to shine on any spoon. Think of the colours on a big perch, especially those bold black stripes or the gleam of gold that is a big common carp held to the sunlight. I hope you're getting to the heart of just how lucky we anglers are and how we must never take for granted even the bluebell tints of a humble gudgeon.

In other ways, our senses as anglers are especially finely-tuned, too. I'm constantly aware not just of wind speed, but more importantly of its direction and the slightest shift of even just a few degrees. A southerly can be magnificent, but it only has to edge round to the east and it turns from friend to foe in minutes. The fish stop feeding, the terns stop skimming the surface for hatching insects and even the cuckoo goes into a silent sulk.

I guess, too, that anglers have the most developed appreciation of sunlight. In the winter, the dour, cloud-covered day that has seen not a single pike come to the net can turn magical if a low sun breaks through at the final knockings. An angler will be looking for that. Equally, a harsh sun in summer can kill things until a veil of wispy cloud covers its face and things turn round magically.

It's not just colours that anglers are particularly aware of. The very best fishermen I've accompanied have an uncanny way of seeing through the water's surface and interpreting exactly what is happening beneath. There is a real skill, much more than a knack, to watching fish. You look at a piece of water intently, cutting every other thing off that happens in the world around you. You go into a sort of trance, I suppose, totally immersed in the piece of water before you, totally open to any movement, however secretive that happens within it. Something happens, something clicks in your brain. Your eyes now bore through the surface film and all your focus is intent on this small sign. You are like a hawk zooming in on its prey. Suddenly, all the secrets of the trout, or the roach, or the chub, or whatever are laid bare. This sounds preposterous, bananas even, but it's true and it happens, believe me.

I also feel sure that anglers have developed some sixth sense, a little voice somewhere in the brain that tells them when action is about to happen. There is no rhyme nor reason to this, but over and over in my fishing life there have been moments when reality seems to be in suspension, when the world rotates in complete silence. You just know that a fish is about to bite. You just know that the peace is about to be shattered. And more often than not, this sixth sense is proven to be right.

Shortly, a BBC2 angling series is set appear featuring Paul Whitehouse and Bob Mortimer on an angling safari. It was my delight to be the fishing fixer, in part because the two of them are just the nicest, wittiest and most generous guys imaginable. But above all, there was one moment I will never forget. Bob had seen his first barbel and he was five again, not 50-odd years old. His eyes were like saucers. For once in his life, he struggled to find the words to express himself.

'It's just bloomin' marvellous,' Bob said. 'Everything about it is sheer magic. It's like a living sword of gold.'

I couldn't have expressed it better, however long I'd thought about it.