In part it is a relief to think that we don’t have to see everything. Certainly we couldn’t notice every detail around us—if we did the world would turn into a fluttering buzzing confusion. But we would also be overwhelmed by just becoming aware that we see everything, without even looking closely. Merely registering that such–and–such a form is a tree, or a segment of sidewalk, or a blade of grass, or a pebble would be enough to overwhelm us from what we want or need to see. Out in the countryside, you might become preoccupied with the species of grass in the pasture, and entirely miss the fact that there are cows as well. On the street in the city, you might be hit by a car while you were checking to make sure each brick in each building really is a brick. In order to be able to see at all, we need to perform these intuitive reductions and omissions. If I see the texture of grass in one place, I assume the rest of the pasture is not barbed wire, and if I see the outline of one skyscraper, I assume there aren’t important gaps in it, or other buildings inexplicably entwined with it. All these operations are the concern of experimental psychologists and neurobiologists; they are the ones who are trying to explain how we can get away with seeing so little.
So I’m happy with this, but I am also a little uneasy. The whole scenario assumes that if I wanted to, I could look at an entire landscape, see the barn and the cows and the pasture and the stream, and finally see everything down to the smallest specks my eye could resolve. When I first thought of doing this, I imagined sitting under a tree and patiently looking at every leaf and blade of grass, until I would eventually fall asleep like Rip Van Winkle. But I have tried it, and what really happens is that I am baffled from the very beginning. If you look at a tree on a distant hillside, you can see it has branches, and you may think you see its leaves, or at least some of them. But are those spots leaves? Or are they bunches of leaves, blended by the distance and by the limits of your eyesight? The strange fact is that you can never inventory a landscape, not even in a lifetime, because most of the objects you think you see are only rough guesses. Those of us who don’t have serious eye problems do not pay much attention to the limits of our eyesight, and even people who wear strong glasses or contacts imagine that good vision is crystal clear, and capable of resolving everything. But most objects are only blurred colours, and we guess the rest.
Our daily obliviousness to the limits of our eyes was brought home to me when I bought a telescope for my apartment. I thought the telescope would let me explore the view better, see the names on the passing ships, or resolve the houses across the bay. But the telescope did not improve anything: it gave me a wobbly, fuzzy view of things I could already see, and as I shifted my position, trying for the best views, I realized the telescope was revealing the limitations of the glass in my windows. (With a window open things were different, and the telescope did reveal many details that had been invisible.) I began looking at the glass in my windows. Thanks to what the telescope had shown me, I could see the way the glass made the world just a little distorted. It was an unhappy discovery: a moment before, I hadn’t given a second thought to the windowpane, and I would have said it was perfectly transparent; now it was like looking through eyeglasses smeared with Vaseline. The distortions of the glass were just barely below what I might have noticed with my naked eye, but when I knew what to look for, they were obtrusive and annoying. I felt a little trapped, as if the window had become an obstacle or a wall, or as if it were a permanent defect in my own eyes. Even now I dislike seeing through those windows, and I always open them to have a good look.
Trying to see a whole landscape produces a similar result. In quick succession you realized that you have not been looking at leaves or grass, but bleary patches you had assumed were leaves or grass. You can never see an entire landscape because views of the world are built from the ground up out of reasonable assumptions. The texture on a far hill will show itself to your eye as if it were trees, but that is only an unconscious assumption, and those “trees” are never composed of leaves and branches. They are phantoms, forms without structure.
All this happens in front of our eyes. Things are even more dubious when it comes to objects we sense out of the corner of our eyes. What do we really see out there beyond the sharp focus of our gaze? In the nineteenth century the master experimentalist Hermann von Helmholtz spent time trying to see, and also to calculate, what takes place at the blurriest margins of the field of vision. It turns out we are acutely sensitive to peripheral motion (in modern terms, the retina has motion detectors at the edges of the retina), so that if I stare straight ahead, and hold my arm out to the right, I cannot see my hand until I wiggle my fingers. The hand out there is not a proper hand: with some effort, I can see it as a flesh–coloured pad with five loose appendages, like a salamander’s paw. (Incidentally, some animals prefer to see motion all across their visual field. If you have a dog, try this game: walk into the woods, and press yourself against a tree trunk. Stay within sight of the path, but keep close to the tree. Then whistle for the dog, and it may run right by you, even within a foot or two, and it may not stop until it loses your scent and realize its mistake. Dogs are very good with motion and smell, and comically bad with static visual patterns. Maybe that’s why they are not interested in pictures.)
Everything at the margins of vision looks higher and skinnier than when it’s seen head–on. Helmholtz demonstrated that mathematically with a clever proof, and you can verify it by standing in a dark hallway with a bright open door exactly to your right or left. Looking straight ahead, the doorway will look too high and a little too narrow. These phenomena tell me that things I see peripherally are not just blurry, but also differently proportioned. They are distorted and hallucinatory, and they need motion in order to exist. The fifteenth–century painter Piero della Francesca said it best when he supposed that everything out there is nothing but a mess of spots. I don’t know much about my peripheral vision because it is a real strain trying to learn about it. It is not easy to look straight ahead and think about what you see in the margins: and I say think because that’s what it is: a kind of seeing that is really thinking. Even though you see whatever is out there, in a way you can’t see it at all until you think hard about it. And that unusual partnership of thinking and seeing feels like something is wrong, like twisting a foot around until it faces backwards. Helmholtz was a kind of hero in this respect, and just reading his book makes my eyes turn red in sympathy: there was a person who really used his eyes.
Even though these experiments can be entertaining, they are really all unhappy thoughts. Your eyes don’t give you the world like a photograph, crisp from one corner to the other. First off, your field of vision has an irregular margin. If you look around, you can see your eye socket: your nose, eyebrows, and even the lower outside corner of your cheek (though that may be a little painful to bring into focus). But that’s not the real issue. What matters is that when you are looking more or less straight ahead, everything at the edges is radically undependable. It’s spotty and evanescent. It’s not just out of focus, it’s dilapidated. And then there’s the problem of resolution: you may think you can see grains of sand on a beach, or threads in someone’s coat, but when you look closely you may be thrown into confusion. It’s hard to realize you have not been seeing familiar objects like distant trees, but drawing conclusions based on tiny samples and guesses. And worst of all, you actually see very little. Out of a panoramic scene, we tend to pick one or two convenient picturesque details or essential objects, and we can scarcely force ourselves to see the remainder.
Still, unless we think of these things we can be perfectly content. I know that if I want to, I can use my eyes up to their natural limits. If I have the patience, I can see everything I need to see. The fact that I am hardly ever aware of these issues does not disturb me, because I’ve been using my eyes to good effect my entire life. As long as I command my vision there is no serious problem: that is, I can live with corrupted vision if I know that I am capable of seeing everything my eyes can resolve, if I need to. But is that really true? Is it possible to look really hard at that distant tree, and say what it looks like? If I hold my hand to one side and look straight ahead, can I concentrate long enough to accurately describe what I see? What are those shifting blurry lights I was calling leaves? Can I throw off the impression that they’re leaves long enough to see them for what they are? Can I force my eyes not to draw conclusions, and see the visual mess for what it is? Perhaps Helmholtz could, but I can’t. It is very hard to see something that has no shape or name: if I try to force myself to suspend judgment about those leaves, I see them as clothes tumbling in a dryer, as a child’s kaleidoscope, as a dirty rug… as anything at all, but not as the nothing that they are.
In this way I come to understand that I see nothing—meaning that the objects I see are constructed out of nothingness, that confusion is the porous stone from which I build visible things. This is a fundamental discovery for me, but it is safely pushed just outside the limits of ordinary seeing. I can choose to notice it, and become perplexed at how I make vision out of nothing; or I can ignore it, and go about my business without doubting my eyes.
Courtesy the author