I’ve recently run through the whole 9 yrds of ocular inspection, and am perplexed as to why the back and forth with the doctor and his A/B first/second is required anymore.
The very first machine they stuck me in showed me a picture of a hot air balloon (way fuzzy of course, as my prescription is about -6). A few seconds later with some automated adjustments, the balloon was clear. I don’t find this completely surprising; light goes both ways, and I don’t see why you couldn’t make a machine with some laser scanner that can read the back of your eye and adjust accordingly.
After that machine though, I still had to go through the interrogation as to which was better, reading the 3rd line, etc. (Especially annoying is that I don’t think the resulting glasses have my left eye perfectly right, and I think I’m going to have to get it reground). Why can’t that first machine do it all? Just like everybody else, I want my glasses to bend light so as to conform to the retina of my eye. Why the math and physics aren’t available I have no idea. Anyone?
Maybe all of the optometrists from Slaughterhouse 5 read Player Piano, and don’t want to automate anything?
Really, I’m sorry that I have nothing to contribute beyond that, other than my casual observation that automation did pretty much do all of the work to determine the correction factors for my LASIK a few years ago. Kind of hard to ask “better or worse” when under the laser.
Because you might not like what the autorefractor (that machine that determines an estimate of your prescription) would prescribe.
I’m taking a class on Refactive and Binocular Case Analysis now, and while you might be easy to satisfy, plenty of people are not. Simply giving people what the machine prints out might satisfy you (or it might not…) but plenty of people would return their eyeglasses/contacts if doctors only did that.
Just some examples:
The autorefractor might over-minus you (i.e.give a more negative prescription.) If you’re young you might not even notice the eyestrain this would cause in distance viewing, but it could become more pronounced in near-vision activities such as reading, where you have to accommodate for long periods of time.
People with high cyl, or a significant cylinder change – that is, people with astigmatism. Many times they prefer to go with less cylinder than they really “need,” according to the autorefractor, because they’re used to less of a prescription. Giving them what the autorefractor says they require can cause an increase in perceived distortions, such as the tilting of walls or ceilings.
Hyperopes, particularly hyperopes with a lot of latent hyperopia – if their vision is fine and they’re young, you can often “ignore” their latent hyperopia, particularly if that is what they want. If they are having trouble with nearwork or if they’re getting older, the process of subjective refraction is necessary to see how much plus they’ll accept as they relax their accommodation.
Those are just three examples; I haven’t even gotten into binocular balancing or anything like that. Suffice it to say that you, the patient, do a better job refining your prescription through your subjective responses than any automatic process has yet managed to do.
I believe that autorefraction is common when they are doing humanitarian work in third-world countries. So we are essentially getting the “deluxe” eye exam.
That and more. Like with shoes I am not really certain of what prescription I like best until I have worn it for a while. I buy my eyeglasses in China where they are cheap and I have plenty I do not use just because I order several and then settle on the ones I prefer. Also, eyesight correction can vary slightly over the day, just like the size of your feet. This is not one, exact, invariable, quantity we are talking about. This is like fitting shoes. Some people like the a bitt looser, some a bit tighter.
I have a tad of astigmatism which I have never wanted to correct but many optometrists would want to sell me that just because the lenses are more expensive.
I have got to the point where I bought (in China) an optometrist’s case with a set of over 200 lenses and the typical adjustable frame. You want to test a prescription for some hours or days before ordering? No problem.
I’m willing to buy that people would prefer to customize their prescriptions like that, but I can’t say I’ve experienced a whole lot of that myself (unless it’s included in the A/B first/second bit). OTOH I’ve only ever been to two optomotrists, so…
But it further occurs to me that if that’s what you’re angling for, why not have something like a set of super-binoculars that lets you focus things yourself, rather than have the optomotrist mess with things and ask? I don’t use my glasses with binoculars, and it takes me only a few seconds to adjust the eyepiece so that everything is in focus. If the idea is to dial in on what I like, why not have something like that?
As well as the practical issues cromulent has cited I think there is the broader issue that plenty of things that could be completely automated, aren’t. People like the service, not just the good in many or most cases. Why aren’t all shops vending machines by now? They have the technology and you could pick what you want and just pay for it without a person there.
The short answer is that it’s fairly easy for the self-refracting patient to make “mistakes” (like over-minusing/under-plussing) that may make things appear slightly sharper (or, more likely, slightly smaller, which many people confuse with looking sharper) but that will only be apparent as an error in refraction once the patient has done a variety of activities with his/her new glasses, including very close near-work, reading for hours on end, etc. There are actually a variety of things people can do with their eyeglass prescription that might appear fine to them until they actually spend some time in their glasses. Even with an eye doctor there to prescribe spectacles, people come back to have a new eyeglass Rx remade all the time (generally,at no cost to them – it’s assumed that what you like in the exam room isn’t necessarily perfect, and you might not realize that until, say, you drive and realize your peripheral vision is distorted, or something like that.)
Add onto that the fact that systemic issues (like diabetes) or ocular health issues (like cataracts) can cause changes in refractive error and, of course, can themselves cause blurry vision, and it makes sense for someone to give an eye exam who can also separate the purely refractive visual problem from anything more serious.
The patient isn’t always necessarily the best judge of when their prescription is correct, anyway. One of my dogs unexpectedly decided to eat my glasses yesterday, so I went in tonight to get a new pair made. It had been almost two years since my last exam, so even though my vision in my contacts seemed fine, I let them talk me into getting an exam first.
It turns out that my prescription in my right eye was completely wrong, and I never noticed a thing! I’m heavily left eye, err… handed, so I have a tendency to automatically let it do all of the work once the right gets too blurry. I went from a -2.00 to a -1.00 tonight.
(Yes, it got better. The doctor and I couldn’t figure that one out either. At my first appointment with her a little over ten years ago, I was at -2.75. At this rate, I’ll have 20/20 vision by the time I hit 65.)
How about DIY adjustable-focus eyeglasses? Heard a spot on these recently on the radio, Here’s a Guardian article on them. According to the article, wearers are easily finding their own preferred prescriptions.
I can agree with this. Whereas I know some people who would much rather have the no hassle grab-it-and-go convenience of vending machines for damn near everything, I often frequent stores that are more on the pricey side simply because the people who work there are helpful, personable, and intelligent. With a vending machine there would be no bad service, but there would be no good service, either.
Exactly. For example, near-sighted patients tend to over-prescribe. The optometrist is not just letting the patient decide, the optometrist is using the answers as part of the overall picture.
I concur with everything cromulent has mentioned so far, I also want to reemphasize that if a patient were allowed to select his or her own Rx as it were often times they could end up with an Rx that would not work for practical purposes. The doctor is going to know all those pesky rules that you cannot expect a patient to see out of glasses that have an Rx with a difference of more than 5 diopters of difference between the eyes. As well as lots of other fun stuff like that. Also, the doctor is checking the HEALTH of your eyes. So you can catch things like diabetic retinopathy when it is still treatable.
On the other hand I am always amazed at the sheer amount of ignorance in people who wear eyeglasses. How can you wear eyeglasses and not have the least curiosity in how they work, what the prescription means, etc. Most people have no idea what each item in their prescription means and I am always shocked by this ignorance and lack of curiosity. I was in my teens when I started wearing eyeglasses and learnt the basics of eye correction lenses in no time.
Whenever I interact with a professional, be it a lawyer, a scientist, an engineer, whatever, I find that the more I know and understand of that field the better we can communicate and interact.
When you take your car to the shop or your eyes to the optometrist, the specialist sees a static picture of the situation at that moment but only YOU have the complete picture of what has happened over time and if you are in a position to understand and explain that it will be of immense value and help.
BTW, for a while, some years ago, I went to an optician who had some kind of device which did not require wearing the lenses but would project an image at a distance that would be focused in my retina. I loved that feeling of seeing perfectly well at a distance with no eyeglasses. I do not know why that system did not spread or what problems it may have had. If anyone knows what it was called I’d like to know more about it.
My guess is that it used a mirror in the distance which would reflect a projector which formed a virtual image at an adjustable distance near my eye and by measuring the distance measured the necessary prescription.
Great article! Those glasses are, quite simply, given to people in third world countries who don’t have any other options. They are problematic for the same reason that DIY prescriptions are – but for someone living in poverty, they are clearly (er…no pun intended :p) better than nothing at all. As a -10 D myope with .5 D astigmatism, I’d rather walk around with, say, -11 than nothing.
Incidentally, I’d be curious to see how those glasses handle a cylinder prescription, and how accurate people are at determining their own axis and cylinder amount. My hunch is, not good at all. But of course plenty of people with spherical or close-to spherical could be helped by them.
They same principle is behind (S)VOSH missions --(Student) Volunteer Optometric Services to Humanity, where large quantities of old glasses collected from Lion’s Clubs and other places are brought to third world countries. From what I’ve heard, sometimes people with less common prescriptions are prescribed a best fit based on what is available, if their own prescription isn’t found among the used eyeglasses. So I guess the presence of an optometrist who can write a unique prescription is just a perk of living in a first-world country. It does seem to me that a more sustainable long-term solution to the issues brought up in that article is to train opticians and eye doctors – or at least, refractionists – in those countries and create an industry so that people could afford to buy their own custom-made eyewear.
I believe it’s also fairly easy to get a “free” prescription done, because the profit on the eyeglasses themselves is so high. That tends to lower the perceived value of the eye exam which then makes an automated system seem unneeded.
Like risha, my vision is very lopsided. My left eye is, for all intents and purposes, normal while my right is, for all intents and purposes, close to legally blind. It’s not lazy eye, that’s just how I’m built.
Anyway, even if the prescription is “correct”, I’m still gonna get woozy because the lenses are way out of line. So I work with the optometrist to make sure that I can a) see well, but b) that I don’t get nauseated or look like this guy. That’s something only human judgment can work out.
