I had very sharp vision in my youth. In my mid-twenties, I started to get near-sighted and reconciled myself to wearing glasses. In my forties, I started to get the far-sightedness that is usual for that age, which for a while nearly canceled out my near-sightedness. Now I can't see well near or far, though my uncorrected vision isn't really that bad: about 20/60.
I was aware it had been a long time since I'd seen the eye doctor, but was embarrassed to find that their records show it has been eight years. Strangely, though my vision had noticeably degraded in the last few years, the visual acuity exam suggested the same prescription. Sure enough, the glasses, when they arrived, were disappointing. They were great for close-up fine-gauge crochet work, but for things more than about four feet out, there was no difference with them on or with them off.
When I went back in, they tried every explanation in the book, up to and including wild variations in blood sugar--not an issue, according to a recent blood test. "Well, have you been wearing the glasses?" Not since I found they didn't make the tiniest difference. "Maybe you're just not used to glasses." Oh, come on, really? I tried them for three days. The only good explanation I could think of was that I'd never before had my eyes dilated before the visual acuity test. The eye doctor's personnel didn't seem to think that could be it, but there's no doubt that when they retested me that day, without dilation, the prescription was quite different and they were able to correct me back to better than 20/20, whereas on the first go-round they could achieve only 20/20 in one eye and 20/25 in the other. In a week or so when the new lenses arrive, we'll see.
In the meantime, I've been trying to read up on whether it's a good idea to dilate the eyes before a visual acuity test. The answer is proving hard to pin down. Have any of you guys run into this?
I just got new glasses (for the first time in seven years, myself). They told me that the old prescription was too strong, and I actually needed milder lenses -- whether my eyes have gotten better, or the last doctor just wasn't very good, I couldn't say.
ReplyDeleteI had my eyes dilated both times, though, because I wanted them to get a good look at the retina as it is an effective predictor of heart conditions and other things. (Good news: I seem quite healthy, for now.) I've skipped it some when I was in my 20s, to save money, but I don't know that I've had any observable differences in outcomes.
I am not a doctor, so take this as just one person's 40 years of experience wearing glasses. I have never had dilation before an exam. It takes a minimum 20 to 30 minutes for your eyes to return to normal after dilation so I have a hard time believing that your exam would not be skewed. I have always had dilation after the exam.
ReplyDeleteMH just had his done for the yearly VA exam, and the place he went to here did both. They did the visual acuity test, dilated his eyes, waited 30 min. and retested. It resulted in a change in his lense strength for one eye. I would think this would/should be the standard.
ReplyDeleteJust my .03...keep the change.
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I've had 20:70 vision all my life; although in the last few years I've had to add reading glasses. Sometimes I've had my eyes dilated before a prescription exam, sometimes not, but the prescriptions resulting always were spot on.
ReplyDeleteHow much do you like this doctor? You might consider a different one. I've never had one, or a GP, that was unwilling to discuss a diagnosis or a diagnostic tool with me.
On your question of the utility of eye dilation, the Mayo Clinic had some words, essentially saying it's for looking at a number of symptoms; it's pretty irrelevant to getting a lens prescription.
Eric Hines
Never had my eyes dilated before an exam- it sounds wrong on the face of it, and here is why- a wide open lens is going to have a much shorter focal length -would not this detrimentally effect eye focus?
ReplyDeletea wide open lens is going to have a much shorter focal length
ReplyDeleteThe dilation opens the pupil--the gap in the center of the iris muscle that admits light through the lens to the retina. Dilation itself does not affect lens shape; the iris overlays the lens.
I'm not an eye doctor, nor do I play one on the radio, though.
Eric Hines
For Grim, I can't remember why, but some people's eyes do improve as they age, my mother being one.
ReplyDelete"I'm not an eye doctor, nor do I play one on the radio, though."
ReplyDeleteBut did you stay at a Holiday Inn Express last night?
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But did you stay at a Holiday Inn Express last night?
ReplyDeleteNot since they lost my reservation, two trips in a row, because they filed my customer number under someone else's name.
Eric Hines
It's not uncommon for near-sightedness to improve in one's 30s or 40s, a time when most people's eyes are gradually becoming more farsighted. My father and I both had that experience.
ReplyDeleteI got my new lenses today, and what a difference! Everything looks crisp and clear right out to the horizon.
PS, I do understand the need for an eye dilation in order to diagnose all kinds of things that require getting a good look in there--but from now on I'm going to require them to complete the visual acuity test first. I still don't understand quite why the dilation would affect the acuity exam, but it certainly did, and it has done for my husband as well. (They tried the "blood sugar" explanation on him, too.)
ReplyDeleteWell, it's because the dilation moves the blood sugar molecules that are in your lenses farther apart....
ReplyDeleteGlad the new spectacles are doing the trick.
Eric Hines
Sort of strange the people in the know don't know.....
ReplyDeleteRaven- the trick is to know you don't know ;)
ReplyDelete