Friday, April 29, 2005

myopia

For those with perfect eyesight, myopia is a thing to worry about when middle age approaches, and more often it is hyperopia (far-sightedness) that afflicts. But myopia isn't really all so bad.

A funny thing is that almost any person with less than perfect eyesight considers his/hers to be terrible. They use adjectives like "very," "extremely," and even "severely" to describe their nearsightedness and moan about how awful it is. Most of these babies have a measurement of -2 or -3 diopters. If it can be treated with LASIK, believe it or not, that's not terrible eyesight. LASIK is effective and pretty safe for treating an eye with greater than (mathematically speaking; a negative number is less than 0) -6 diopters.

The diopter scale measures from -30 to +30 (I believe) with 0 being perfect. Very few people hit the extremes of the scale, just as with any bell curve. My measurements are -13.5 and -14. Which is genuinely bad and makes me laugh at the babies, but is not yet blind. In practical terms, anything more than 4 inches away starts to get fuzzy at the edges.

Myopia on this scale has some really neat benefits:

You have a built-in a magnifier. You can stick a ladybug, or a opal, or a Russian lacquer box two inches away from your eye and see beautiful detail in an enormous size.

Lights are not lights, but something that looks like a perfectly round glowing amoeba. Mysteriously, the amoebas are pretty much the same size no matter the size of the light you're looking at. A small light, an LED for example, will be dimmer amoeba than a stoplight, that's all. The amoebas shrink and grow based on the contractions and expansions of your own pupil. If you stand still and watch closely, you will see the amoeba pulsing to your heartbeat.

Looking at morning light through trees is an experience bordering on exquisite.

You can still see objects quite well; you simply have no crisp detail or edges. You home in on colors and shapes, and other senses kick in as well – you can pick up a small bird from its motion, discern from its movements that it's a sparrow and not a dove. However, discerning a sparrow from a chickadee is impossible, because they're about the same size and move similarly.

Perhaps because of the habit of trying to find patterns with uncertain vision, a myopic person can see shapes that take some effort for normally-sighted people to pick up. I can find human faces and animal shapes in trees, quilts, anything with a complex and irregular surface.

I never know quite how to react when myopia is depicted in the movies. Nerd loses his glasses and he instantly starts imitating the Mummy, pawing the air before himself and stumbling, might as well have a paper bag on his head. Sometimes it's funny, sometimes it disgusts me because it's not like that at all. In theory, I could drive my neighborhood without my glasses: I can discern pedestrian-sized blurs, dog-sized blurs, red blurry stop signs, and amoeba stop lights. One of these days someone should make a movie scene where the nerd loses his glasses and keeps going, and when someone comments on the loss, asks, "Do you really believe everything you see in the movies?"

And sometime in the next year, I'm going to lose all that. I'm waiting for FDA approval of a phakic intraocular lens, or PIOL. This lens is inserted under the cornea, which allows the person to continue to be able to focus near and far, unlike cornea replacement. The first lens has been approved, but my surgeon is waiting for a second lens to meet approval, one that he believes is better for my eyes.

After that, I'll be able to wake up in the middle of the night and see everything. It'll be an amazing experience, I'm sure, having had poor eyesight nearly all my life. But I'm going to miss the amoebas, the magnifying glass, and morning light through the trees.


Postscript: anyone with -8 diopters or poorer vision should really look into PIOL. If your vision is this bad, you need very thick corneas to withstand LASIK, which reshapes your cornea by lasering off bits. You may end up with severe halos in your night vision. Do not let the low price or a LASIK surgeon sell you on this procedure until you've considered PIOL implants. Visit the complicatedeyes.org website for questions on any type of eye surgery.

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