January 10, 2013

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A new window of the sole

monofocal interocular lens“I see,” we say, when we mean “I understand.” To make something “clear” is to make it vivid and unmistakable to the mind’s eye. There are no limits to the ways sight serves as metaphor for many good and necessary things in life. The importance of vision, even for the sightless (who still use language), is beyond full accounting. As creatures we are exceptionally dependent on vision. For us upright walkers sight is, literally and figuratively, out topmost sense.

It is also through our eyes that we express ourselves and make connections with each other. That eyes are windows of the soul is so well understood, and so often said, that no one author gets credit for it.

Yet some of us are more visual than others. Me, for example. One might think me an auditory or kinesthetic type, but in fact I am a highly visual learner. That’s one reason photography is so important to me. Of the many ways I study the world, vision is foremost, and always has been.

But my vision has been less than ideal for most of my adult life. When I was a kid it was exceptional. I liked to show off my ability to read license plates at great distances. But in college, when I finally developed strong study habits, I began getting nearsighted. By the time I graduated, I needed glasses. At 40 I was past minus-2 dioptres for both eyes, which is worse than 20/150. That was when I decided that myopia, at least in my case, was adaptive, and I stopped wearing glasses as much as possible. Gradually my vision improved. In 1999, when the title photo of this blog was taken, I was down to about 1.25 dioptres, or 20/70. A decade later I passed eye tests at the DMV and no longer required corrective lenses to drive. (Though I still wore them, with only a half-dioptre or so of correction, plus about the same for a slight astigmatism. They eye charts said I was then at about 20/25 in both eyes.

My various eye doctors over the years told me reversal of myopia was likely due to cataracts in my lenses. Whether or not that was the case, my cataracts gradually got worse, especially in my right eye, and something finally needed to be done.

So yesterday the lens in my right eye was replaced. That one was, in the words of the surgeon, “mature.” Meaning not much light was getting through it. The left eye is still quite functional, and the cataract remains, for now, mild.

Cataract surgery has become a routine outpatient procedure. The prep takes about an hour, but the work itself is over in fifteen minutes, if nothing goes wrong, which it usually doesn’t. But my case was slightly unusual, because I have a condition called pseudoexfoliation syndrome, or PEX, which presents some challenges to the surgery itself.

As I understand it, PEX is dandruff of the cornea, and the flakes do various uncool things, such as clog up the accordion-like pleats of the iris, so the eye sometimes doesn’t dilate quickly or well in response to changing light levels. But the bigger risk is that these flakes sometimes weaken zonules, which are what hold the lens in place. Should those fail, the lens may drop into the back of the eye, where a far more scary and complicated procedure is required to remove it, after which normal cataract surgery becomes impossible.

In the normal version, the surgeon makes a small incision at the edge of the cornea, and then destroys and removes the old lens with through a process called phaceomulsification. He or she then inserts an intraocular lens, or IOL, like the one above. In most cases, it’s a monofocal lens. This means you no longer have the capacity to focus, so you need to choose the primary purpose you would like your new lens to support.  Most choose looking at distant things, although some choose reading or using a computer screen. Some choose to set one eye for distance and the other for close work. Either way you’ll probably end up wearing glasses for some or all purposes. I chose distance, because I like to drive and fly and look at stars and movie screens and other stuff in the world that isn’t reading-distance away.

The doctor’s office measured the dimensions of my eye and found that I wouldn’t need any special corrections in the new lens, such as for astigmatism — that in fact, my eyes, except for the lens, are ideally shaped and quite normal. It was just the lenses that looked bad. They also found no evidence of glaucoma or other conditions that sometime accompany PEX. Still, I worried about it, which turned out to be a waste, because the whole thing went perfectly. (It did take awhile to get my iris to fully dilate, but that was the only hitch.)

What’s weird about the surgery is that you’re awake and staring straight forward while they do all this. They numb the eye with topical anesthetic, and finally apply a layer of jelly. (They actually call it that. “Okay, now layer on the jelly,” the doctor says.) Thanks to intravenous drugs, I gave a smaller shit than I normally would have, but I was fully conscious the whole time. More strangely, I had the clear sense of standing there on my retina, looking up at the action as if in the Pantheon, watching the hole in its dome. I could see and hear the old lens being emulsified and sucked away, and then saw the new lens arriving like a scroll in a tube, all curled up. As the doctor put it in place, I could see the lens unfurl, and studied one of the curved hair-like springs that holds it in place. Shortly after that, the doctor pronounced the thing done. Nurses cleaned me up, taped a clear shield over my eye, and I was ready to go.

By evening the vision through that eye became clearer than through my “good” left eye. By morning everything looked crystalline. In my follow-up visit, just 24 hours after the surgery, my vision was 20/20. Then, after the doctor relieved a bit of pressure that had built up inside the cornea, it was better than that — meaning the bottom line of the eye chart was perfectly clear.

Now it’s evening of Day 2, and I continue to be amazed at how well it’s going. My fixed eye is like a new toy. It’s not perfect yet, and may never be; but it’s so much clearer than what I saw before — and still see with my left eye — that I’m constantly looking at stuff, just to see the changes.

The only nit right now is  little rays around points of light, such as stars. But the surgeon says this is due to a bit of distortion in my cornea, and that it will vanish in a week or so.

The biggest difference I notice is color. It is now obvious that I haven’t seen pure white in years. When I compare my left and right eyes, everything through my left — the one with the remaining cataract — has a sepia tint. It’s like the difference between an old LCD screen and a new LED one. As with LED screens, whites and blues are especially vivid.

Amazingly, my computer and reading glasses work well enough, since the correction for my left eye is still accurate and the one for my right one isn’t too far off. For driving I removed the right lenses from my distance glasses, since only the left eye now needs correction.

But the experience of being inside my eye watching repairs in the space of the eye alone — sticks with me. All vision is in the brain, of course, and the world we see is largely a set of descriptions we project from the portfolio of things we already know. We can see how this works when we disconnect raw sensory perception from our descriptive engines. This is what happens with LSD. As I understand it (through study and not experience, alas), LSD disconnects the world we perceive from the nouns and verbs we use to describe it. So do other hallucinogens.

So did I actually see what I thought I saw? I believe so, but I don’t know. I had studied the surgical procedure before going into it, so I knew much of what was going on. Maybe I projected it. Either way, that’s over. Now I don’t see that new lens, but rather the world of light refracting through it. That world is more interesting than my own, by a wider margin than before yesterday. It’s a gift I’m enjoying to the fullest.