A side note about "getting your numbers"... The author remarks, "she’s not happy to share the measurements with me as she fears I’ll run off and get my glasses made online".
This will obviously vary by jurisdiction but what the author describes may be illegal in some places. e.g. where I live, there is a law since 2010 requiring opticians and optometrists "to give clients, free of charge, a copy of their prescription, sight-test assessment or contact-lens specifications — whether or not it is requested by the client — and also to give a copy, free of charge, to a third-party eyewear seller or other person if requested by the client"
I think you can ask for it, but they will only give it begrudgingly.
In other words, it's not part of the prescription, it's instead part of the glasses fitting process.
A non-eye related example would be if your doctor prescribed you a brace and the person at the medical supply store measured you to find out which size you need.
I measured by taking a picture of my face with a credit card for reference and measuring the pixels with the measuring tool in GIMP. (These were the actual instructions on the website I ordered my glasses from.)
Also worth mentioning I paid $40 ordering them online, in the article it says he paid $280!
I was amazed because until a friend told me about this site, I've been paying hundreds of euros just for the frames! At such a low cost, I could even order slight variations on the strength.
They have a lot of options for better lens material, have it darken in sunlight, anti glare coating etc, but I just got the cheapest one and it was fine.
This means the frame must be chosen and fitted to you before any of these are measured.
It becomes a 2D measurement.
There is a lot more to it (vertex distance, pantoscopic tilt etc) but the above is the absolute minimum.
Ed: i see @andai made a similar comment.
Might indeed be better to use a "long" object to indicate pixel length by division (credit card is 5432 px = 5 cm) rather than going by a ruler which might typically only be accurate to 0.5mm at best anyway.
When you go to an optician, the doctor takes you in the back and determines your prescription. Then you go out front to the showroom and pick out your frames. There is usually a technician out there who will take the PD measurement and combine it with the prescription, and frame and lens selection to make your order. The technician is also the person who fits you with the new glasses when they arrive.
if not, sounds like a startup idea.
I'm sure it could be done better, but boy, that was an interesting experience I hope to never repeat.
Much easier than trying to get someone to measure it accurately with a ruler in front of your face, or trying to draw dots with a washable pen in front of your eyes on old glasses, or any of the other methods I tried. The measurement I took appears to be accurate (the glasses I ordered from Zenni using it are comfortable to wear), and it was easy to get a precise and repeatable measurement to within about half a millimeter.
> In both the UK and most of Canada (excluding British Columbia), the PD measurement is classed as a dispensing tool rather than a part of the actual prescription of the person whose eyes were tested, thus there is no obligation for a PD to be provided on patient request.
most places that sell glasses do those for free tho. I agree they should be given out and they do in europe, or at least in the two states I lived, but being paid for is not the angle to come at it from
So it's a paid-for thing; I don't feel bad about taking the prescription and buying glasses online. That said, the glasses from the shop last way, way longer than the online ones, so I really just use online for sunglasses or like to get novelty frames for a costume or something.
So you're still getting the information that requires special training or licensing, and you can get the other information yourself if you really want it.
Especially in the context of psychotherapy or when using placebos, this makes a lot of sense.
Having worked in the medical field in the past exploring a DICOM dataset was no challenge, and the end result is I have a rotating 3D-view of my own brain! (Well just blood vessels, but still ..)
I've heard the same thing about hearing aid prescriptions, CT (and similar) scans, and blood test results. In Canada they'll happily give you the results for your own records, but apparently some other countries don't provide it as a general right, leaving businesses to decide whether they want their competitors to be able to pick up work they initiated.
I think the difference is whether medical is private or public.
I imagine the healthcare system plays against you in your country
My real concern is if I encounter some problems, if I got the exam and glasses from one place, I can insist they fix it for me instead of arguing who is at fault.
I share his, uhm, perfectionism regarding optical corrections, and it's led to quite some anxiety. I feel like eye exams here aren't done with a lot of care, and that they just aim for "good enough". I'm not sure what to do with the knowledge that you can buy such an optician kit and test yourself. It's either a great or an absolutely terrible idea.
Not too surprisingly, independent small batch production runs of frames end up costing a lot of money.
There are also artisan frame makers who hand make the frames. If you are going to pay $300 for some frames, mine as well get an actual work of craftsmanship.
At the end of the day, most Luxottica frames are actually far cheaper than the high end independent frames you can buy. Exceptions are the fancy branded frames, but at that point the $ is for the Gucci logo.
Online bare bones frames also exist, or just go to Costco.
A 3x-4x markup at retail is normal. For low traffic businesses, an even higher markup is needed to stay in business.
Those online stores do a lot of volume, and don't have to pay leases or for nearly as many opticians to be on staff.
> that the prices we pay for eyewear in no way reflect the actual cost of making frames and lenses.
Of course it doesn't. The price we pay for eyewear is the price we value it at. Just like literally everything else that is sold in stores that isn't a commodity good.
Doesn't help that insurance is involved. $200 a year eyeglasses allowance. Eyeglasses end up costing $200. Is anyone surprised?
This is how I excuse spending $250 on a mech keyboard and using high-end smartphones/laptops.
Not buying super expensive new cars, or any cars, is probably the best place to not do this. Unless you commute daily.
In reality, it's pretty hard, because very few stores have much selection at all to look at. After a number of years of buying their frames every once in awhile, I found an optometrist who invited me to "meet the sales rep" so I jumped at the chance; turned out it was a co-owner and also a model for the company's materials, he brought basically every frame they owned to the meeting, told me great stories, made great recommendations. It was the amazing experience I had been looking for but not finding. Just gotta get lucky, I guess, with smaller companies.
I supported Frameri through their crowdfunding and beyond for this reason. I bought several sets of interchangeable frames and lenses from them and am pretty satisfied. But then they closed up shop and left me hanging with a never-fulfilled final order. :-(
The article mentions a +7 in one eye, we’re in the 1.67 index range (mine are 1.6) with a script like that. €208 is a deal.
Not to say that $200 isn't a great deal compared to Luxottica, and he did say that he was very particular about his frames, but $200 still seemed high.
I work freelance as a colorist and re-recording mixer – both are professions which are highly based on perception. And it is certainly true: if you try to really go into the details of something, be it color, sound or anything else, it already helps a lot if you sharpen your senses to these things. I always say: you don't pay me for beeing able to use some software, you pay me for having developed my senses over years in a way that others didn't.
Measurements at different points in time can differ slightly: in the morning just after I wake up I get some values, after staring at this monitor for 12 hours I get slightly different results. I always make the glasses from the morning measurement, but luckily the values rarely differ from one year to another (I change the lenses every year on the pair I wear on the motorcycle, riding with the visor up I get the lenses scratched in about one year from the dust in the air).
Indeed! The best thing you can do before an eye exam is be rested, eat an apple, don't stare at your phone in the waiting room, look out the window if there is one.
Tired eyes will give differing results. Low (or high) blood sugar (even in healthy people) with give differing results. Straining your eyes by looking at a screen in the waiting area can give differing results.
Note for all these I say can and not do.
When I go to my $$$ optician, the technician marks my pupils on the blanks in the frame that I've selected using a sharpie (before the glasses are made) and adds the inter-ocular measurement to the glasses information. When I put on the resulting glasses, I don't have any eye strain symptoms and my vision is good (instantly).
When I went to cheap storefront glasses places (I don't do that any more) and I put on the resulting glasses, I get a "stress" signal from my eyes and then they adjust to work with the suboptimal glasses but the eye strain is always there.
And, if your optician is close by and shares your belief that your values vary over time, getting your values checked in different "states" (morning / evening / tired / etc.) can be helpful for deciding on what the "right" values for your glasses may be.
Still an interesting read, just not what I expected from the title and lead.
Apple makes it's own SoCs for the iPhone, only Apple can't make semiconductors. They provide specifications to a manufacturer. Apple makes the iPhone, except it's Foxconn that manufacturers it.
The APU in the Xbox One is made by Microsoft, but it's composed primarily of off the shelf designed CPU and GPU cores from AMD and manufactured by TSMC/GF/<insert foundary>.
My natural expectation was that the author made his/her own lenses and fitted them into a frame. Or designed their own frame, ordered the parts and then assembled them into a frame. I was expecting a technical rundown about all the steps it took to do something like that.
The blog post is still a fun read, but the title is definitely misleading.
No, what the OP did was check/confirm his numbers and then bought a pair of glasses from a website. Many people buy them from websites, typing in the numbers they received from their doctor. None of these people are “making” anything.
Your examples of an Ikea Sofa and Pizza are great examples of either end of the spectrum. An Ikea sofa has finite configurations that could all be permuted into model numbers, the parts are interchangeable and swapped between models, and prefabricated. A pizza however is completely made to order on demand and if there's a mistake the components are nonrecoverable waste.
With Apple's custom SoC, they're designing a custom circuit however that specification is sent to someone else to manufacture. At it's core, it's not unlike ordering a pizza of astronomically greater complexity. So what makes a custom pizza just an order and not a make? Is it the relative simplicity/complexity of the task?
If I enlist a factory in China to manufacture custom mouse pads based on my exact specifications, did I make a mouse pad or just order it? Does it matter if the mouse pads are just press cut fabric backed neoprene in various colors and shapes?
Glasses are somewhere between an Ikea Sofa and a Pizza in terms of modularity. The lenses and frames are off the shelf but once cut the lenses are spent if an error is made. Glasses however have much more exacting specifications than a pizza or a Sofa.
>Luckily, I didn’t have to.
There's a specific reason why they do this and ask you to make a decision in an instant. It's called accommodation. Your eyes will quickly try and accommodate and find focus if they're allowed to stare too long. This could explain the reason he got such different results from the exams. He was trying too hard. Just follow directions.
> One more thing. Do you remember the process in which an optician makes you wear a new pair of glasses and stares at you with this optician-look, takes the pair of glasses away from you again, goes to the back office and starts bending parts of it in a seemingly random manner, comes back, hands you the pair of glasses which now suddenly fit perfectly?
> Yeah, I attempted to do that with my new pair of glasses and noticed that I suck at it. I would bend it to look similar like the glasses from the optician only to realize that the back of my ears were hurting after a few hours of wear.
Is he really a Doctor??? He doesn't know there's a Mastoid bone there that the "bending" (aka: Adjusting) the optician is doing is to AVOID putting pressure on that bone!?
As other comments point out, medicine is a very specialized field nowadays and I didn't specialize in any field (I got into coding healthcare software instead) - in Germany you study all disciplines at University (min. 6 years) and then specialize during something comparable to US residency in a hospital.
I understand the process of accommodation. This poses the risk of e.g. over-correcting short-sightedness if you're not aware of it because, with each lens of increasing strength, you accommodate and think "geez, everything just got sharper.. again!". I was aware of this and, as you can find in my article, actually ended up using very similar values for dioptries (the spheres) as the opticians. So either all of us totally forgot about accommodation or all of us were aware of it :)
My values mainly differed regarding to astigmatism, and accommodation doesn't play a significant role there.
I am also aware of the bone behind my ears, thanks for reminding me :)
While you do learn a lot of stuff in med school, learning how to bend those things of glasses which go behind your ears is not part of that. I suppose that's not a skill which can be taught well, anyway - it's more like craftsmanship, getting it right by having done it lots of times.
Good job and interesting story!
As a side note: for optical reasons, the spherical equivalent of the lens (which will determine if you are overcorrecting or not) is calculated by adding the sphere value + half the cylinder value (whatever the axis value).
You ended with a correct prescription as far as I can tell by looking at the different measurements , however you did not totally grasped the optical subtleties of the accomodation process : astigmatism is important (a small overcorrection is not a big deal anyway)
It is usual to undercorrect the cylinder values given by the autoref and your ophthalmologist would have given you the right prescription I think.
I'm just saying that to underline that as I doctor myself, I'm usually very wary at thinking that I can fully understand, in a few days, what my colleagues do. I'm totally into the hacking spirit but let's stay careful, especially for more dangerous things than glasses.
Also cyl/sphere differential is also hard to determine but often follows a pattern in that you can overcompensate in sphere for cyl and vice versa.
Not even going to begin to go into the effects of possible tolerance differential, prism imbalance, and that is just with Single Vision Lenses.
Also you generally have 90 days as industry standard to go back and retest your RX.
In German, "ophthalmologist" is "Augenarzt", which is literally "eye doctor" (Auge: "eye" + Ärztin: "doctor").
Well, that's settled, then. ;)
> I understand the process of accommodation. This poses the risk of e.g. over-correcting short-sightedness if you're not aware of it because, with each lens of increasing strength, you accommodate and think "geez, everything just got sharper.. again!". I was aware of this and, as you can find in my article, actually ended up using very similar values for dioptries (the spheres) as the opticians. So either all of us totally forgot about accommodation or all of us were aware of it :)
Well, minus does like more minus. (Ask your new optician friends).
> My values mainly differed regarding to astigmatism, and accommodation doesn't play a significant role there.
No, but squinting, even a small amount, does. If your axis favors it.
> I am also aware of the bone behind my ears, thanks for reminding me :)
> While you do learn a lot of stuff in med school, learning how to bend those things of glasses which go behind your ears is not part of that. I suppose that's not a skill which can be taught well, anyway - it's more like craftsmanship, getting it right by having done it lots of times.
Indeed. That's why there are professionals who do it. If you are still going to do it at home and you have a plastic frame, heat the ends up slightly. You can microwave a damp rag and wrap it around the ends for a moment. Or use a hair dryer carefully. At the optician's office, they have a hot air blower that does it. Used to be they had glass beads, but those got in between lenses and caused no end to trouble. If you bend cold tips, they can more easily break.
I apologize for questioning your credentials. I guess I was a bit harsh. I just feel the article came off mostly of a slight arrogance with only a smattering of humility. You seemed to think that you could make up for years of working in the industry with only a few days of playing around. That being said, congratulations on being mostly successful. However, I am sure I don't have to tell you that an eye exam is only partially to refract you. There are other health issues that can be detected by having a routine eye exam.
Doctors are pretty specialized today, and he has a list of publications on his site, right in front of you, so that may be an excessive reaction.
I think that's a little harsh. I took it to mean he realized he had no idea how to properly bend it, and pointed out an optician is the expert here.
You are right. It can be an issue in the other direction though.
People are checked after often sizeable waits looking at the same thing (their phone, the wall, outside) for a long time.
When you then start the switching lens tests, there will be a set of lens optimal for your current situation, and a different set of lens that would fit better for a long day of doing whatever you are usually doing with the glasses on.
Knowing how good a pair matches after accommodation is equally valuable, IMO.
Please consult with a medical professional.
I don't have a long experience with glasses but I have never received these instructions and my experience is similar to the author.
More or less jokingly we showed up with chains on the last day to bind him to the desk :) we allowed him to part after a couple of beers though.
Yes its super painful to lose talent.
If you were out wandering the streets or looking at random things with no constraints you would be overwhelmed with choice and it would be very hard to draw a conclusion. You may decide what's right is based on looking at something, only to find out after all of that something else 4 days later looks way off because you didn't see that during your real world test. You end up being individually burdened with making the decision instead of letting science do its thing.
The only issue I have is frames because it's very possible to get frames that are comfortable for the few minutes you try them on in the store but they end up being horrendously uncomfortable after a day or few days of usage (even after many adjustments).
I don't know how to solve that problem though because in order to wear the frames for a long test period you would need to be able to see, which means your real lenses need to be placed inside.
I've done this with several pairs, and the main thing is you need to heat them to get the plastic into a temperature where it will hold a new bend. I've used a hair dryer for this, though you need to be careful not to over-heat them or the plastic will blister.
You can also go into a glasses shop and ask if they can adjust them, though when I tried this they wouldn't take my money and just did it for free, which I felt bad about.
I've brought probably 10 frames there multiple times over the last couple decades, only one of which I actually bought there.
> O: “Honestly, I have no clue. Maybe. Maybe not? The letters look similar but different.”
 Reprahsing to make it clearer:
will it be possible in the future to measure objectively?
I believe wavefront guided LASIK uses some kind of automatic method of determining refractive error called an aberrometer. Some ophthalmologists have a device called an i-profiler that they use as part of their assessment which appears to be an aberrometer.
Everything I've read on the matter seems to me to indicate that there is possibly some kind of hybrid automated autorefractor/aberrometer type technology that could be created to give fairly objective and accurate measurements of refractive error with no human operator, but given that legally an ophthalmologist would need to sign off the prescription anyway the upside is probably limited.
This optician used Zeiss a i-Profiler to make i-Scription lenses (https://www.zeiss.com/vision-care/us/for-eye-care-profession...) They've worked better for me than any of the subjectively-measured prescriptions.
I would imagine that, no matter how the brain were processing the image, the image being focused exactly on the retina is an objective truth, and that an exactly-focused image must be clearer to the brain than a blurry image.
Imagine creating a lens system for a camera where you can't control for one element. That element is dynamic with a reasonable autofocus that suffers from time varying accuracy and range of performance.
We need dynamic correction. Glasses with auto/adjustable focus.
No it's subjective - I think that's the main point of the article.
There are other parts of the exam that are more related to eye health, but I don't see why they vision prescription process and the eye exam have to be combined. How many people that don't wear glasses ever get their eyes examined?
No it's imprecise - again that's a key point of the article. The author finds that there's a lot of variance in the measurements obtained.
I totally agree that having an objective way to measure this would be awesome.
Let's say I go to a bad optician and get a pair of lenses that have something way off like the cylinder is the wrong way around, or toric lenses for astigmatism when you actually don't have it. Everything looks like crap but then you get used to it (the brain is amazing at adapting). Then a few years later you go get another pair, and they use the lensmeter reading as the baseline.
I think I have astigmatism, or do I? It took me more than two months until I stopped getting headaches after getting my first glasses and I could see decently. Every glasses since then are based on that first reading. Maybe I've just become used to it, and there exists a significantly better lens that I could become used to as well.
Maybe the failure rate is low enough that it is not worth it to improve the process...
The initial prescription and the final one are only a little different when you consider the change of acuity they can deliver (from a physics perspective). For a script like that, the frame choice, lens design and vertical placement of the optical centres (if the frame is a little deep) could all have a similar effect on acuity.
It is also very common for there to be differences like he found between an auto-refraction and a subjective refraction.
It’s possible that they are too focused in on the prescription itself and there are issues around the lens positioning/design that are involved here as well.
After determining exact spherical diopter, then test for astigmatism by spinning a set of parallel black lines on a white field, and parallel white lines on a black field. Or just look at a printout of an astigmatism dial chart.
I've been going to the same ophthalmologist for several years now and over that time he's made a few mistakes in the script; twice I've had to have the glasses remade because of errors on his part. He came highly recommended, but the recommendations you get tend to be aligned with whatever hospital system you get them from, rather than true recommendations based on actual craftsmanship.
I'd be interested in figuring out how to find an ophthalmologist who uses the Zeiss i.Scription tool in combination with a subjective test. I probably need to start going first thing in the morning as well; since I have to have my eyes dilated I tend to go in the afternoons after I've been hacking code most of the day; it sounds like that could be hurting the quality of the prescriptions.
If anyone in the Detroit Metro knows of a good ophthalmologist with the Zeiss machine, do send me a note.
This is ridiculous. Why should I not be given the value measurements that have just been made?
That's why I bought my own optician test lens set and now do the measurements myself. I can also test these measurements over a long period of time looking at a screen for example.
I've had people stop short of saying I should be arrested and that I'm doing something illegal.
The cost, one or two visits to the optometrist.
>Trial lenses: A large number of lenses with varying corrections
>Trial frame: A pair of glasses without lenses into which you can insert the trial lenses
>Turns out, you can order these kits online from very trustworthy Chinese resellers for around 190€.
Seems like it would be nice to have these available for rent. I would rent that for 20 euros a week, and after 10 rent-outs it has payed itself back
It's a small effect, but it is noticable.
The best eye "hack" I've done is getting Lasik. I wore glasses and then contacts for about 20 years and got Lasik done 3 years ago. It's worth whatever it costs you.
I hate this! Are they really allowed to do this?
"What's my prescription?" "Not telling"
I read in this thread that elsewhere on the planet, they're not free, and then of course you get the values. Would be super weird to pay for a test and then not get the result. (Nobody likes vendor lock-in.)
I've done eye tests before and not gotten glasses because it turned out not to be necessary, but it always felt really shitty. I always asked how much it was, as an offer to pay, but was never asked to pay anything. I'd be in favor of paying for what you use to avoid both guilt trapping and hard feelings.
I've never been able to get a good fit for my contacts although my glasses have always worked well enough. The weird thing is that when I go to get contact lenses, the retailer orders them according to my glasses prescription, but subtracts seemingly arbitrary values from it to arrive at the contact lenses' values.
I live in Pakistan, btw.
Then, check whether they are over- or under-correcting and order another pair with slightly different values under the assumption that your initial "best guess" was off. Then, compare and repeat..
With not-so-bad astigmatism, you can get away with not correcting it in your contact lenses. That's what I currently do. It works okay and brings you to a good level of vision (1.0 here in Germany, probably 20/20 in the US).
The shifting position isn't a problem, I think the bottom-heavy ones adjust fine with a little bit of practice, but the experience is never that good.
Hopefully shops with 3D printers etc. will give consumers more repair options.
From personal experience: don't do these tests if you're tired, have headaches or are otherwise impaired. For example if your eyes simply want to shut and you're forcing them to open the musculature will affect your vision.
I'm not looking forward to the "does this look better or worse?" dance and can totally relate to the author's frustration!
> Want to optimize your medication? Read up on all relevant studies and guidelines.
I am surprised to have seen this penned by a doctor. Relevant studies and guidelines are a minefield for amateurs.
I've also received lenses that don't match the prescription. My ophthalmologist says that source of error is common. So now I have the doctor's office verify my lenses.
> As a doctor I know some things about the human eye
Something about these sentences identify our author here as German. And low and behold, it turns out he is.
Maybe variation can be attributed to that.
On the contrary, it seems totally logical. If the difference is so small that you can't assuredly decide between two options, either will do.
>How can a trustworthy decision be made in this not-real-life scenario of staring at letters on a wall? I want to be able to decide while going about my daily routine: Staring at computer screens, looking out of the window, looking into space. My daily routine doesn’t include staring at the same five letters projected onto a white wall and reading them out loud.
Yeah, so? Who told you you'll find anything more doing that, that you would looking at the projected letters?
>I went through with it and the pair of glasses arrived around two weeks later. Putting them on for the first time, my vision was just as perfect as with the trial lenses. Awesome! This was hands-down the best pair of glasses I ever had. Better yet, it was the first pair of glasses with which I could see better than with contact lenses (as those don’t have a cylinder).
For all the skepticism at others (eye professionals at that), did he checked his enthusiasm for placebo effect? Or the IKEA effect for that matter?
The guy seems eccentric in a creative way, but unbearable...
Yes. I have two pairs of glasses here: The optician-made ones and my self-prescribed ones. I have controlled for the frame - both have the same one.
I see much better with my self-prescribed ones. If you don't believe me, feel free to drop by and we'll do a blinded (heh) test. :)
A slightly different way to interpret this would be to say that that particular axis of variation is at its limit, given the state of the other axes.
There are several axes, and they aren't perfectly orthogonal. Zeroing in on one can alter the best correction achievable on the other. Not all opticians will go back and iterate other axes, but I think it's a good idea. Lock X, find Y, recheck X given Y, etc.