Week 12Summer Week 12
Earth teems with sights and textures, sounds and vibrations, smells and tastes, electric and magnetic fields. But every animal can only tap into a small fraction of reality’s fullness.
—Ed Yong, An Immense World
Stop!” I say, grabbing my husband’s arm and pulling him back. It is Rascal’s last walk of the night, and we are taking a path around the neighborhood that we have taken every night for years. It is as familiar to us as the way through the dark house that leads from our room to the rooms where our children slept. But now something has flown out of the night and landed just where Haywood’s foot will fall with his next step. He stops. I open the flashlight app on my phone.
On the street crouches an obscure bird grasshopper, a large insect aptly named. Ask me how I know this, and I will tell you about the time an obscure bird grasshopper flew into my pollinator garden while I was weeding. I looked up expecting to see a wren.
I squat to look more closely. Grasshoppers cannot turn their heads, but this one shuffles its whole body a quarter turn to look back at me. “It’s hard to believe there’s anything wrong with your eyes,” Haywood says for what is probably the thousandth time in our marriage. “You saw that bug in the dark!”
In fact there are many things wrong with my eyes. To see small creatures, I look for signs of disparity, or I follow some new sound or motion. If something isn’t clearly distinct from its surroundings, or if it isn’t singing or running or crawling or flying, I will almost certainly miss it.
I have limited depth perception, a consequence of uncorrected amblyopia in childhood. And lodged in the optic nerves of my eyes are structures called drusen, which, like amblyopia, are congenital—in time they may cost me my peripheral vision. Drusen likely caused my mother’s macular degeneration and may have been the reason her brother lost his vision to ocular hemorrhages. My grandmother went blind from a hereditary form of glaucoma. The genetic legacy from my father’s side of the family is more devastating—a very high risk of cancer—but I don’t dwell on that possibility. It still feels distant to me, more theoretical than real. The family history of blindness, on the other hand, I think about more and more often as I leave midlife behind. The accruing indignities of a body that is no longer predictable makes it hard not to ponder what other burdens might lie ahead.
And now I have cataracts, too. This is a common problem for people in the last third of their lives, of course—a problem that’s easily remedied, at least for the fully insured. It is nothing to panic about. I panic anyway, just a bit. The specialist who monitors my vision tells me that he can remove the cataracts before they get worse, before they begin to interact in a more troubling way with everything else that’s wrong with my vision. Already a new blind spot has turned up on the elaborate testing I undergo every year, though it’s still unnoticeable to me. Almost all the effects of cataracts have been invisible to me so far because I have grown accustomed to incremental change, to vision that is always a little worse from one year to the next. I order new glasses, spend a few days getting used to the updated prescription, and then stop thinking about it. I see what I can see. I have no way of knowing what I cannot see.
The world is becoming dimmer to me whether I am aware of it or not. Colors are fading. I can no longer remember a time when the streetlights did not have halos. The doctor entices me with promises of brighter colors and crisper lines. Good God, I think, how much more beautiful the beautiful world would be with even more color! Within hours of having her first cataract removed, my mother could not stop marveling over the flowers. They were her own flowers, but she had not yet seen them for what they really were.
I am afraid. I have lived with the fear of losing my sight since I first understood my family history, and there is a non-zero risk—as my sons like to call a very small chance—that this ordinary and safe operation will make my vision worse. How could I bear to see even less?
Even with perfect vision, a human being’s ability to perceive the world through sense experience is limited. A red-tailed hawk can see a mouse in the grass from a hundred feet in the air. Raccoons have four times as many sense receptors in their hands as we do. To keep songbirds from crashing into our storm doors, I put up stickers impregnated with a chemical that reflects ultraviolet light, which birds can perceive but people cannot. I watch Rascal sniffing and sniffing at the same spot in the ditch at the edge of our yard, and I know that another dog has marked it. Rascal can tell if the dog who peed there was male or female, healthy or sick, calm or agitated. I can’t tell another dog was ever there.
Animals have many, many ways of apprehending their world that I can imagine only poorly, if at all. The way the pupils of a Cooper’s hawk dilate at the sight of prey. The way a robin migrates by tuning into the earth’s magnetic field. The way rattlesnakes can find their prey by following infrared radiation. The way bats send sound waves into the dark, and the way what comes back to them is the shape of the world. I think of the marvelous compound eye of the housefly, creating a mosaic from thousands of images. For a housefly, the world is a work of collage art, patched together but whole and hopelessly, extravagantly beautiful.