Yet Another Cycling Forum
General Category => The Knowledge => Health & Fitness => Topic started by: Sergeant Pluck on 25 January, 2022, 09:21:03 pm
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It’s new glasses time and one of the local opticians gets good reviews so I availed myself of their services. While I thought I had mentally prepared myself for the extent to which my wallet could be depleted, I nonetheless find myself looking at less costly options.
Does the following contain enough information, aside from pupil distance, to order glasses online? Could one order varifocals armed only with this plus pupillary distance?
R Vision: 6/9J +1.00 / -0.50 x 100.0 6/6 Add + 2.00 N5
L Vision: 6/9+ +0.75 / -0.25 x 55.0 6/6 Add + 2.00 N5
Pupillary distance - any success with home measurement using an app or selfie? How accurate does it need to be, and how would one know if the PD was wrong?
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yes, that is enough. I use select specs, and have been happy with their quality. I use their cheapest (something like £6) for reading glasses, as I find the PD being accurate helps a lot over off the shelf reading glasses
(ETA - just checked and they start form £15 now)
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PD: I measured mine in a mirror with a ruler and used the result online for many years. During a recent optician visit I asked them what they got and they told me 4mm more than I had measured.
I use binoculars a lot and, on reflection, thought that would be a better measurement, and sure enough, got the same as the optician.
I have worn (all day) specs with both measurements and don't notice the difference, but I don't have a large correction.
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If you can get your hands on ANY binocular equipment (binoculars, microscope etc) and read the scale, that's a win.
Getting the optical axis correct is more critical with high prescriptions but still makes a difference for weaker lenses, like yours.
A friend with a ruler might get a more accurate reading than you can get by yourself.
Pupillary distance does not change once growth is complete so any ANCIENT record after the age of 25 would be OK.
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No
The missing measurement is the height of your pupils.
This is really important, and can only really be determined on a particular frame.
I think you need a min of 10mm from top of lens, but check with optician.
Varifocals are bloody expensive. Cheap varifocals are carp.
Your prescription seems mild.
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No
The missing measurement is the height of your pupils.
OK, thanks. Makes sense for varifocals. I now remember the optician measuring that when I bought the current pair. I wonder how the online places deal with that requirement?
It may be mild, but it’s less mild that it used to be for distance.
Helly and hbunnett, I have binoculars but 1) the scale isn’t very good, just dots every 2mm and the pointer doesn’t reach the scale and 2) it’s hard to pin down the most optimal point. But it certainly gives a number, 64-65mm, that is in line with a measurement done on an app that I’ve tried since my first post. Perhaps any method that doesn’t involve looking into the distance means your eyes will be directed inwards, putting off the measurement.
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The eyes converge for close up vision.
I don't personally recall this being measured by my own optometrist.
65mm is towards the small side for a man IIRC.
It's quite possible that some suppliers will just supply for 68-70mm and hope, which is suboptimal
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I didn't get on with the varifocals I bought online, the transitions just seemed wrong and the fit wasn't comfortable. I was able to return them for a refund so there was no risk. I didn't take up their offer to have another go, they were so far from right that I'd lost confidence and went back to the High St chain opticians.
Next time I needed glasses, I was recommended a shop that sells them but isn't an opticians (There's probably a name for that but I can't think what it is), prices about half way between the opticians and online and the service has been excellent. After choosing a frame they mark the plain lenses up, I'm not sure what for, but it works and it's a step completely missing from the online process, as is the fitting when they're collected. I don't know how common such shops are, but it might be worth checking out.
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Leaving frames aside, is £400-ish typical for varifocal lenses - Essilor I think? London, but not an optician that seems to pitch itself at the top end.
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The eyes converge for close up vision.
I don't personally recall this being measured by my own optometrist.
65mm is towards the small side for a man IIRC.
It's quite possible that some suppliers will just supply for 68-70mm and hope, which is suboptimal
That’s what I mean - if measuring PD when looking at something close, a webcam or phone app, then surely the measurement will be lower than if measured when looking into the distance, as is the case when the optometrist does it.
As Paul H says, once the frames are selected, there is some sort of lining up and marking process on dummy lenses in the chosen frames.
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Leaving frames aside, is £400-ish typical for varifocal lenses - Essilor I think? London, but not an optician that seems to pitch itself at the top end.
I paid about £400 for my last two pairs of varifocal specs. Outer London, independent optometrist
Cheapest possible frames
Anti-reflective coating
Lightweight high-index lenses.
You won't really need high index with your prescription.
Anti-reflective coating is recommended.
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I think my last pair were about £400, Boots own frames & Zeiss best lenses. That was a couple of years Pre pandemic though.
I need a new set as well. They seem to have recently developed lots of tiny scratches, I’m not sure if the coating is breaking down.
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I pay just under £400 for varifocal lenses.
My prescription is high enough that I have to get the more expensive high refraction index lenses, which adds to the cost.
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Apologies in advance for going slightly off topic.
I got my first pair of varifocals about 6 years ago from a local chain of opticians. They explained how the "middle distance" bit of the lens, in the middle of the lens can vary in width depending on how much you want to pay, the wider the more expensive, and then suggested that as it was my first pair and I had never used varifocals before that I get either the cheapest or next cheapest (so a fairly narrow middle bit) which is what I did. Scroll forward two years and I took my new prescription to a company who make the lenses for a lot of opticians but now also sell direct. I had bought a pair of prescription sunglasses from them previously and they were great to deal with and a bit cheaper. I gave him my prescription for the varifocals and waited to be asked about the width of the middle bit but he said nothing, so I asked him about it. He looked blankly at me and then explained that when they grind the lenses they can only grind them one way which produces a set width in the middle depending on the prescription required. That left me wondering if the first opticians were really just giving me a choice of four different prices for the same lens.
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Apologies in advance for going slightly off topic.
I got my first pair of varifocals about 6 years ago from a local chain of opticians. They explained how the "middle distance" bit of the lens, in the middle of the lens can vary in width depending on how much you want to pay, the wider the more expensive, and then suggested that as it was my first pair and I had never used varifocals before that I get either the cheapest or next cheapest (so a fairly narrow middle bit) which is what I did. Scroll forward two years and I took my new prescription to a company who make the lenses for a lot of opticians but now also sell direct. I had bought a pair of prescription sunglasses from them previously and they were great to deal with and a bit cheaper. I gave him my prescription for the varifocals and waited to be asked about the width of the middle bit but he said nothing, so I asked him about it. He looked blankly at me and then explained that when they grind the lenses they can only grind them one way which produces a set width in the middle depending on the prescription required. That left me wondering if the first opticians were really just giving me a choice of four different prices for the same lens.
I do not think that is completely accurate as there are multiple types of glasses. For instance I have a standard varifocal on one pair which varies from perfect distance at the top to close reading at the bottom. My other pair has computer distance at the top and then a little bit further away in the bottom half specifically for working on the computer and then examining patients. My wife has driving, general and computer glasses all with different focus points.
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Just got my first varifocals too
Great service in the past from https://www.glassesdirect.co.uk/ to get the frames and "normal" glasses. But had brilliant service from https://www.reglaze-glasses-direct.com/ and even a sweetie in the box when I got my glasses reglazed.
I got a pair for outside walking and driving and they work great with watching telly and being able to read my phone and other small print. I also got a pair that is nearly varifocals for 'puter work (read the screen and being able to do small screws on mobiles or other small faffs) Though I'm not 100% sure about them yet.
Best part with reglazed you can try out for a few weeks and they will reglaze if you don't like for free. I would say give them a buzz and talk to their staff.
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Apologies in advance for going slightly off topic.
I got my first pair of varifocals about 6 years ago from a local chain of opticians. They explained how the "middle distance" bit of the lens, in the middle of the lens can vary in width depending on how much you want to pay, the wider the more expensive, and then suggested that as it was my first pair and I had never used varifocals before that I get either the cheapest or next cheapest (so a fairly narrow middle bit) which is what I did. Scroll forward two years and I took my new prescription to a company who make the lenses for a lot of opticians but now also sell direct. I had bought a pair of prescription sunglasses from them previously and they were great to deal with and a bit cheaper. I gave him my prescription for the varifocals and waited to be asked about the width of the middle bit but he said nothing, so I asked him about it. He looked blankly at me and then explained that when they grind the lenses they can only grind them one way which produces a set width in the middle depending on the prescription required. That left me wondering if the first opticians were really just giving me a choice of four different prices for the same lens.
I think that the second opticians is talking nonsense. If they only sell one brand of lens, with one type of lens material, then it might be true for that brand.
My first varifocals had Zeiss lenses. There were different qualities of Zeiss lenses, and the brochure made it quite clear on the differences.
Some optimised distance vision, with very small middle distance, and reading part.
I opted for the most expensive, which basically were better all round but particularly for the middle distance (computer use). As I'd be using them a lot when working (e.g. in meetings, when I needed to look at my comp screen, whiteboards and what I was writing), flexibility was important to me.
At lot of the variation is due to the refractive index. High index, higher price. Whether they charge more because they can, or whether the lens material is more expensive (or more difficult to work), I don't know.
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I paid £460 for my last two pairs - high but not super high refractive index, one pair in self adjusting sunglasses mode, mid price frames. There is, of course, a discount to make the second pair feel less expensive. That price included someone taking a look around in my eyes and checking the prescription (which isn’t changing as fast as it was, but enough to need a check every couple of years).
They did reject one set of frames that I chose, on the basis that they couldn’t make the various focal bits line up with my eyes in the available lens space.
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I just go for a separate pair for reading. The cost of a second pair (for reading) at
Vision Express is £20
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If I just needed something for reading, I'd get reading glasses.
I need:
One prescription for distance
One prescription for middle (computer screen or car dashboard)
One prescription for close work like reading
This isn't unusual. People with simple deterioration can use bifocals.
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I had a general pair of varifocals, but found that I struggled playing the piano - where the focal area was too small to adjust to looking at the music after looking down at my hands to work out just what was going wrong. I now keep the general varifocals but also have a limited range one for reading, computer and piano work. As no one really sees those ones and they don't leave the house - they have cheap frames and none of the protective lens stuff etc. That reduced the price signficantly, I think they were less than half the other pair.
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Partner just has plain (therefore cheap) spectacles optimised for keyboard use.
It was initially something of a struggle to convince the optician what was needed was a prescription for a face to screen distance of (I think) 75cm.
The middle section of varifocals lacks the vertical depth needed to keep much of a score sharp.
D uses these 'intermediates' for both piano and computer..
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I had to send my glasses back first time around*, because the default distance didn't fit for me, to get my glasses re-adjusted.
*and remembered to let them know I that I sit further back from monitors than others the second time around. Do people really sit that close to monitors?
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If I just needed something for reading, I'd get reading glasses.
I need:
One prescription for distance
One prescription for middle (computer screen or car dashboard)
One prescription for close work like reading
This isn't unusual. People with simple deterioration can use bifocals.
That’s where our prescriptions differ as my “reading” glasses prescription covers prescriptions 2 and 3 in your list, though my distance glasses are fine for the car dashboard.
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Piano glasses were a game changer for D.
He has plain 'distance specs for cycling and reads comfortably without spectacles.
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Strong prescription varifocals here. £546 recently for two pairs. (Titanium with bendy flexi hinges).
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You can measure PD quite accurately with a pair of glasses and a marker pen.
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Today I called in on a couple of other opticians to get an idea of whether the first optician's prices were typical. It seems they are - £400, 500 and up. I didn’t really find the alternative opticians very helpful on the frame choice front so went back to the first for some more trying on of frames. Not a single one strikes me as being “right”. But I did settle on a strong contender - and the price for varifocal lenses, scratch resistant, anti-reflective, with those frames was £730.
I just can’t see how that is justified. I think that’s more or less twice what I paid for my existing glasses, similar spec, 6 years ago. The frames in question are sort of half framed Silhouttes which I am not certain about in any case.
Back to the drawing board. I’m reluctant to go down the online route with varifocals; I can see it working for a reglaze when you can send your existing glasses to them for the PD and height. But that assumes your existing glasses are correct.
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I’ve no personal experience of them, but Asda & Costco both have optician services which have a reputation for good service & value for money.
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I made sure I received my measurements info when purchasing specs recently as I intend to try Asda next time. They seem to have fixed pricing for most things. Only certain branches have Optical services so check before you travel (Doh!). On line providers seem to service the distribution curve median range only. Not sure about Costco being any cheaper but worth a look as I am a member.
Looking at some of the prices quoted above I seem to have done well which makes it a tad less painful. :-)
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Well I eventually bought new glasses.
Fucking hate them.
Going to have to start again.
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Well I eventually bought new glasses.
Fucking hate them.
Going to have to start again.
Sorry to see this!
Can you list points where these glasses don't 'work' to prevent future problems?
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If these are your first varifocals, they really take a while to get used to them. A case of 'reprogramming' your brain I think.
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My first varifocals were dreadful!
The optometrist, in his wisdom, had decided to undercorrect my myopia by 0.25D, leaving me unable to read the surtitles at an opera we attended.I needed full-strength distance correction.
Buying single vision distance glasses was inexpensive and MUCH better!
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Two problems really.
There is no doubt that, overall, the lenses are what I need. Middle and longer distance is great. But the reading end of it is not so good. The optometrist did warn me about this, and was of the view that it would be best to use my existing glasses for this (they are “office glasses”, good for close work and up to the width of a small room, lets say). But I am finding that I don’t want to have to use 2 sets of glasses. It could be that some further adaptation is needed - I think I need to get used to keeping my head still and looking down with my eyes more. And the truth is that I have not really allowed time for that adaptation at reading distances.
Which brings me to problem 2, the reason why I haven’t put the time in with them: I don’t like how they look. I like them less and less. They fit well, of that there is no doubt, and not many frames do. They sit well on my glasses-unfriendly hooter, often a problem, and in theory they are the right shape for my face, and all that. But I just can’t get used to them. I’ve gone from something much like this (random google find)
https://pretavoir.co.uk/collections/starck-glasses/products/starck-sh1365x-0022
To metal frames, roundish lenses and they just make me look... not me.
I also need prescription sunglasses so I am toying with the idea of seeing if these frames would be better suited to that purpose.
The new ones are excellent for one specific request that I had - that they work well at 3.5m, the distance to my TV.
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I can understand frames not suiting but that's obviously too bad now.
My experience with varifocals was that that the optical 'sweet spot' was very narrow, both vertically and horizontally, which meant much neck movement, which I dislike.
I don't think using just one pair of spectacles is always a realistic prospect past the age of 50 for some people. (I'm fine at home, spending much of my day glued to my seat and laptop…)
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If you don't mind me asking where were they from & what did they cost ? I need a ballpark figure for new ones.
I think I'm going to have to replace mine shortly. Becoming increasingly bad for reading & screen work, and there is now a pattern of scratches(?) all over them which is annoying. Looks like the anti reflective coating or whatever is crazing up. If you run a fingernail over the lens you can feel it.
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Two problems really.
There is no doubt that, overall, the lenses are what I need. Middle and longer distance is great. But the reading end of it is not so good. The optometrist did warn me about this, and was of the view that it would be best to use my existing glasses for this (they are “office glasses”, good for close work and up to the width of a small room, lets say). But I am finding that I don’t want to have to use 2 sets of glasses. It could be that some further adaptation is needed - I think I need to get used to keeping my head still and looking down with my eyes more. And the truth is that I have not really allowed time for that adaptation at reading distances.
Which brings me to problem 2, the reason why I haven’t put the time in with them: I don’t like how they look. I like them less and less. They fit well, of that there is no doubt, and not many frames do. They sit well on my glasses-unfriendly hooter, often a problem, and in theory they are the right shape for my face, and all that. But I just can’t get used to them. I’ve gone from something much like this (random google find)
https://pretavoir.co.uk/collections/starck-glasses/products/starck-sh1365x-0022
To metal frames, roundish lenses and they just make me look... not me.
I also need prescription sunglasses so I am toying with the idea of seeing if these frames would be better suited to that purpose.
The new ones are excellent for one specific request that I had - that they work well at 3.5m, the distance to my TV.
You're so vain.
But seriously, there's only a certain range of vision that varifocals can compensate. When your prescription exceeds what is possible you have to make compromises. In the end you may find 2 pairs of glasses more acceptable. One pair for reading, one for distance.
Alternatively, you could try "varifocal" contact lenses, especially if your "hooter" is a problem, though in my experience these are even more problematic.
Really, it's all about coming to terms with ageing. Good luck.
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I'm not sure you are right about varifocals only compensating for a specific range. I found with the several pairs I've owned that the comfortable clear vision is in roughly an hourglass shape. So the middle distance has the least coverage. That's the distance for computer use and I work all day to desk. So I have a pair of glasses specifically for work. Single vision optimised for screen distance.
For all of the use general daily wear, I use my very focals and have no problems reading, seeing the distance, etc
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I hate these varifocals when I got them, and was in most of a mind to send them back, but life intervened and resulted in inadvertent perseverance.
Anyway, I'm now happy with them now, my brain has figured out how to position my head to look through the correct area of the lens. Seems fine with the computer, reading and for distance vision. Owl-like positioning of your head to optimize the process is something your brain as to learn, but eventually it becomes automatic.
Multifocal contacts lenses, on the other hand, have been awful, I'm not sure what they're supposed to do, but in my experience they don't (I do have very high prescription though, it takes light so long to get through any lens that I'm seeing the past).
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I've tried mono-vision contacts and multi-focal contacts. Awful, and I have a pretty low prescription. Varifocal FTW, and luckily I manage with only 1 pair, even sitting at screens most of the day.
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Ouch, that was an expensive day. £548 for varifocals & £50ish for a pair of reading specs.
Boots in Liverpool. I told them I’d think about it & they said they could give me a 20% discount, but only if I ordered there & then. I suspect their pricing & discount schemes are just to confuse people.
Top of the line Zeiss lenses & a pair of fairly standard gold coloured frames from their “designer” selection.
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That £ sounds about right. And yes, opticians have mastered the art of confusion for the customer, but staying the right side of consumer law.
I gave up on varifocals some years ago although I can't remember why (probably cost). I have happily been using bifocals since.
Having said that, in recent months I've been using eBay sourced reading glasses for my phone and for reading. I've just ordered a £4.49 half-moon pair to try, for when I'm sketching.
Ebay reading glasses from UK suppliers seem perfectly good to me (and, yes, I know my prescription).
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You’d think that it’d be all computer controlled when producing the lenses and that the cost wouldn’t be any more than single vision etc.
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You’d think that it’d be all computer controlled when producing the lenses and that the cost wouldn’t be any more than single vision etc.
Most single vision are 'off the shelf' and just cut to fit the frame. They get more expensive if you have astigmatism combined with long or short sightedness.
Most varifocals are bespoke lens grind and polish.
Economies of scale and all that.
I'm not convinced by the premium prices for 'high density' lenses (which are essential for high strength lenses). It is all just plastic and seems that it would be as cheap to make all lenses with high refraction index plastic.
Using low refraction plastic for some and high for others strikes me as being a way of making money.
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Mine cost about £750 with all the markups – the biggest leaps, if I recall, were for the high-refractive-index lenses and seamless multifocalism (they probably have a better name for that). There's no real way to make an informed decision, is there really any difference other than £150 between the branded lenses etc. and the basic HRI lenses? They just shoved the brochure in my hand. The staff are there to up-sell and, I assume, work to a degree of commission hence their urgent need to sell you 'designer' frames (just normal frames that cost £50 extra because they say Calvin Klein or somesuch on them).
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You’d think that it’d be all computer controlled when producing the lenses and that the cost wouldn’t be any more than single vision etc.
Most single vision are 'off the shelf' and just cut to fit the frame. They get more expensive if you have astigmatism combined with long or short sightedness.
Most varifocals are bespoke lens grind and polish.
Economies of scale and all that.
I'm not convinced by the premium prices for 'high density' lenses (which are essential for high strength lenses). It is all just plastic and seems that it would be as cheap to make all lenses with high refraction index plastic.
Using low refraction plastic for some and high for others strikes me as being a way of making money.
But is this grind and polish done by hand or someone just enters the numbers into a machine a bit like CNC for lenses? Economies of scale is often just the cost of tooling etc forming a smaller and smaller part of overall costs, plus your making full use of your wage slaves. You can also have less profit per item to cover your fixed costs. Once you have the tools in place and the tools can easily be used to produce varifocals (without massive disruption to single vision batch production) then you are also benefitting from the scaling.
If the latter I can’t see where the several hundred pounds extra (above single vision) comes from. If the former and someone grinds and polishes varifocal lenses for 10 hours at £50 per hour, you can see where the cost comes from.
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The basic lenses they do from stock on a machine you can see whirring away in the back of the shop (a garden variety Vision Express). For mine, they to order them from somewhere else (presumably wherever these are made, mine are Zeiss lenses) – aspheric grinding and the ZEISS computer-assisted OPTIMA technique, apparently.
https://www.zeiss.co.uk/vision-care/better-vision/understanding-vision/how-are-spectacle-lenses-manufactured.html
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I was quoted a 3 week delivery as the lenses are made to order in Germany.
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Pretty sure mine took that long too. They did, for the money, do a good job.
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I buy Asda varifocals now, frames cheap as chips and varifocal at same price as std lenses. Very small sweet spot but my brain now adjusts immediately, though I'd almost given up on some very spendy local specialist optician's wide angle (or somesuch geekspeak). With me it was just a matter of (some) time until my brain 'got it' now I can adjust in seconds to a new pair. The biggest expense in my glasses now is the transitions with anti-glare, hard coat etc. I've never tried bi-focal in anything other than dark tinted sunglasses as my wife days the bi-focal line in clear glass makes me look old, I'm 60 had so I'm' hardly a kid!
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I’m getting used to them. First step was to swap the nose pieces to silicon ones, as suggested by the optician, so that they actually stay put. They didn’t have the right nose pieces when I collected the glasses, and that definitely hindered the adaptation process. The lenses do what they were intended to do (i.e. give me a little bit more strength at the close end and a very slight help for distance) although my previous specs, which were “office glasses”, do have less distortion at the sides.
Looks wise: well, they do fit well, probably better than the previous glasses on the nose, and I am getting used to the look.
The only remaining change I’d like to make is another readjustment of the earpieces to minimise contact with my hearing aids. There are acrylic sections at the ear so amenable to bending with a bit of heat. Dithering over whether to do this myself.
So it looks like it is on to the next stage, which is to get prescription sunglasses.
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Just seen this thread. At my last eye test the optician asked me if I had right of reading glasses, bifocals or varifocals. Shocked me as I pay £280 for glasses and most of that is high index lenses, highest they do as standard. I asked if I needed them she said that I probably didn't right now but it's something to think about for the future.
Fast forward and it is 2 years later and I'm planning another eye test. After hearing that my sister got a pair of varifocals for £280 from the chain I use and said they're very good I started thinking. It's been getting harder to read things and I am probably putting it all off for no good reason. So I'm going to ask about them.
My question here is what issues come with having a complex prescription? One eye is -10.25 the other is -9.75. Both were -10 or worse but one eye slipped below that -10 level a few eye tests ago.
I need high refractive index lenses, I think 1.74. Is this possible with varifocal lenses? Is it going to be expensive? Eye wateringly so?
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My varifocals are high-index and pricy but I'm nowhere near as myopic as you.
I suspect it's possible BUT at your prescription, centring the lenses with your eyes HAS to be spot on (distortion is proportional to the cube of the power of the lens) and varifocals give poor correction off-centre.
I'm hoping your optometrist can get things right first time but you might need to pester until they are right.
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I’m in the minus 7s and I didn’t leave with much change from £750. That was basically for the most expensive everything because I’m, erm, worth it or something.
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Yes you can get high-refractive index varifocals.
The price will be eye-watering.
The pupil location in the lens (vertical and horizontal) is absolutely crucial. You can't do this at home, it has to be measured in the frames you will be wearing.
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I think £758, though that was a few years ago and I'm sure they're not cheap. I think the only thing I didn't get was the weird blue coating because they just make the skin behind them look like the colour of liver failure.
The other thing is that with a prescription that high, you're limited to small frames, otherwise they'll will be so heavy that your face ends up down by your navel which makes getting them right a bit of a faff and requires some skill – not something you're guaranteed in today's modern opticians, which are basically frame showrooms staffed by bored teenagers. Someone, one day, will explain why I need frames with a 'designer name' or brand on them because I'm sure I don't. It also makes the lenses more difficult to get used to, you have to train your brain to be very precise. When it comes to training, my brain is basically a cat. I'm happy enough now, though given the number of scratches I've inflicted on them, I probably need a new pair.
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When considering the value you should also be aware that the prescription for the near sight is likely to change quicker than that for the other distances. I'm sure others will have a better grasp of the biology, my understanding is the eye muscles used to focus weaken and that is continues though not linier. My first two pairs of varifocals needed replacing in under two years, my current pair are still usable after three, though I'm probably overdue an eye test. My long distance prescription has been the same for twenty years and little change on the medium distance. I'm still using my seven year old varifocal sunglasses which are fine for everything except that near vision. I did consider that next time round I'd get separate reading glasses, but the convenience is such that I probably wont, I will tick less of the extras boxes than I would have for single vision that have always lasted me 5+ years.
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The problem with presbyopia is that the lens stiffens. This stiffening is pretty rapid around the age of 50.. Once it is totally rigid, reading prescription won't change much.
Varifocal lenses NEED to be quite tall to accommodate near, middle and distant zones usefully and smoothly so lens size will be a compromise...
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Mine are, he says measuring them, 2.5 cm from top to bottom. I'm not bragging.
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Well my prescription puts the thickest part of the lens at the outer edges, corners more precisely. My glasses are generally wide and not too big vertically to reduce lens thickness. Do varifocals come out thicker than similar single vision lense?
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I don't think mine are any thicker and it's normal for the lenses to be thicker at the edges, that's how they work (if you are short-sighted).
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But it is made worse by the prescription. As I got told by an optician, a larger blank disc with equal thickness edges gets ground down to your prescription. The focal point on that blank can be in the centre or more to one side. Mine is more to the inside which makes my lenses a lot thinner on the inside edge but conversely thicker on the outside edge. More central prescription it can be thinner all round I guess.
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Well my prescription puts the thickest part of the lens at the outer edges, corners more precisely. My glasses are generally wide and not too big vertically to reduce lens thickness. Do varifocals come out thicker than similar single vision lense?
No.
They'll usually be thicker at the top if you are short-sighted, as steeper concavity is needed for distance correction than for close-up vision.
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Well my prescription puts the thickest part of the lens at the outer edges, corners more precisely. My glasses are generally wide and not too big vertically to reduce lens thickness. Do varifocals come out thicker than similar single vision lense?
No.
They'll usually be thicker at the top if you are short-sighted, as steeper concavity is needed for distance correction than for close-up vision.
Just taken my glasses off to check. With the glasses inches from my face I can clearly see that they're thicker on the outside, especially on the corners of the slightly rectangular glasses. If they were round there would be a thinning to point inwards of the centre before thickening a little. Since they're wider than higher there's an even me pronounced effect.
Trust me I've got good enough eyesight close up to see they're thicker in n the outer edges and especially the corners.
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Helly means that varifocals Will be thicker at the top corners.
The reading prescription will be much weaker so it will gradually thin down the outside edge towards the bottom.
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Aah! I misunderstood. Thanks for the explain.
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I’m in the minus 7s and I didn’t leave with much change from £750. That was basically for the most expensive everything because I’m, erm, worth it or something.
Yeah my Dad's were something like that, although he did also insist on transition lenses particularly because he wasn't buying 2 pairs at varifocal prices.
Weird as feck seeing him without glasses now the cataract surgery's been done and fix it at the same time.