I only vaguely remember my first visit to an optometrist, at age eighteen. I suppose he put drops in my eyes to dilate them, but I didn’t have to drive myself home (I don’t remember if my father took me or if I took the bus). I do remember an eye exam a few years later, and how difficult it was to drive home afterward, especially on unfamiliar streets (it was my first visit to that eye doctor), with all the lights seeming to stream out in every direction.
I made a point, from then on, not to schedule eye exams in the evening, so that I wouldn’t have to drive home in the dark. Of course, once we moved from greater Philadelphia to rural Michigan, evening appointments weren’t an option anyway. By then there was a second set of drops being used, as part of the test for glaucoma. These drops anesthetize the eye as well as adding a yellow dye that, until today, I always noticed but never knew what it was for. Different offices I’ve been to use somewhat different equipment for this test, and some of them mildly unpleasant and some a bit more so.
At the end of one of my eye exams in Michigan, I found my vision so blurred that I couldn’t even see well enough to write the check to pay for the office visit. I had to have the office clerk write all but the signature and position my hand in the right place to sign it.
Still, getting drops in my eyes is nothing compared to having to help my younger son get them. He can’t stand getting even water in or around his eyes – when he bathes I have to frequently hand him a towel so he can dry his face. Helping him relax enough for the optometrist’s assistant to put drops in his eyes is quite a challenge.
This morning I had my annual eye exam, and there were no drops. None at all! New high tech equipment has eliminated the need for either kind of drops, at least on a yearly basis and for healthy eyes. (My doctor will still use them on me perhaps every three years.) And he assures me my eyes are very healthy, as the results of his high tech tests show.
First they used a new machine that, the assistant explained, could determine the right prescription for my eyes. Remembering what a tedious process it usually is to figure out just what prescription is needed (“Does #1 look better, or #2? Now how about this one, or that one?”), I was intrigued that a machine could figure it out just by looking at my eyes. I stared obediently at the red bulls-eye in the middle of concentric yellow circles, and tried to imagine light bouncing off something inside my eye to tell the computer how much correction would be needed.
Next she used a handheld instrument that, I was happy to hear, eliminated both the yellow drops and the machine that went with them. It did something right near my eyes, and I wondered if perhaps there was still perhaps a tiny puff of air each time it clicked, but if so it was so slight that there was no discomfort at all.
They don’t turn over the entire process to computers, however. The eye doctor still had me sit and look through that big lens-filled contraption and asked “Is #1 better, or #2? This one, or that one?” But after just a couple questions and answer on each eye, he said, “That’s what I expected.” Apparently my responses confirmed that the machine had correctly figured out my prescription (and that it has hardly changed since last year).
And he still had to have me cover one eye and stare at his ear, while he flashed a bright light around in my eye. I don’t know exactly what he’s looking for, but apparently he was happy with what he saw. He also was happy with the results of the digital retinal imaging, an optional test they have offered each year (since I came here in 2005), and which I elect to use every other year (to save money, since insurance generally doesn’t cover it).
When I was all done, I left the office, my eyes happily undilated. And I started wondering just what was all that marvelous new technology I had just experienced. I hadn’t asked what anything was called, so I am not certain I have found exactly the right descriptions on the internet (except for the digital retinal imaging, which I know because I have to sign a special form when I decide whether to have it done or not each year). But I have a much better idea now what the optometrist’s equipment is called.
The machine that figures out my prescription is apparently an aberrometer, which uses wavefront technology. It “fires a low-intensity laser into the eye. The light is reflected off the retina through the cornea and lens, and is directed back into the aberrometer to measure the wavefront. The wavefront data is then used to calculate the optical fingerprint of the eye and produce a customized prescription.”
The big contraption that it helps replace, or at least reduce the use of, is a phoropter. This was a wonderful advance in optometry when it was developed some seventy or eighty years ago, and it will no doubt be a standard in optometrists’ offices for many years to come – especially in parts of the world where expensive high tech equipment is just not an option.
I’m less certain about the handheld device to check for glaucoma, but I’m pretty sure it’s a kind of tonometer. Those other machines I didn’t like were tonometers also, since they all measure the fluid pressure inside the eye, but there are several different technologies available (applanation is the one that requires the yellow dye). From the wikipedia article, I’m guessing the one I experienced today must use rebound tonometry, since it says this is the only device of its kind that doesn’t require local anesthesia.
I’m sure my 9-year-old will be very happy also, next time he gets his eyes checked, not to need any drops put in his eyes.