need feedback re: cataract surgery & correcting for near vs far vision

You quote a price in $ and reference Medicare, so I assume you are in the US (this is a global site, and there are no multifocals approved in the US that correct for astigmatism (so I'm unsure why there would be any reference to it on the lens identifier card, perhaps you read something wrong).

You imply in "3" that you have astigmatism  , and correcting that even with the current lens might improve your visual quality potentially (though sometimes a small amount of myopic astigmatism lends a benefit without much blur, its possible yours is hyperopic and making things worse, or too large and adding blur).  I'm not sure if the "and/or LR" was a typo and it meant "and/or LRI" since an LRI (limbal relaxing incision) is one method to correct astigmatism... which can be done after cataract surgery. Some surgeons will do in their office at the slit lamp. Its a minor procedure  since it doesn't involve doing anything inside the eye like cataract  surgery does. Some surgeons prefer to do a laser incision. 

You don't state what degree of monovision you had prior to surgery, how many diopters difference there was, how near the near eye was focused. The near add for the multifocal lens you received is +2.75 at the IOL plane, which is about +2 at the corneal plane. If you had been given monovision, its likely they wouldn't have given you a difference of more than that for your myopic eye, so it isn't clear that your near vision would have been any better with monofocals in monovision, and may likely have been worse. It may be that your natural lens gave you greater depth of focus than an IOL would and so you had better near vision than you would have even if you'd gotten monofocal IOLs in monovision. 

Neuroadapation can improve near vision for some people with multifocals over the first few months.  It is possible to do a bit of monovision even with a multifocal if the near point isn't near enough. A laser correction could focus the near point in further than it is now, while not impairing your distance vision in that eye as much as full monovision with a monofocal would.

If you get good distance vision with the 2nd eye, that can leave you with good distance vision overall since usually the combined image from both eyes is at least as good as the best eye (not always). One important question is what the "best corrected" vision is, can they   correct your vision using glasses or contacts, or a laser enhancement, to be 2/20. It'd be ideal to not need to wear correction, but the most important issue is whether it can be corrected.

It sounds like the lens power they chose was off, though there is a slight chance that your vision was reduced due to the eye still healing from surgery.  

Unfortunately there is no exact formula to determine the right lens power for an IOL, it is based on statistical analysis of eye measurements of prior patients and what power worked for them. The formulas usually tend to work well for those with low prescriptions, but there is more risk of error for those with high prescriptions (either because of less data for them, or there are some indications there may be issues with some measurements being off for those who are highly myopic). Those who have had lasik due to having a high prescription have changed their cornea, but their internal eye measurements are still like someone with a high prescription,which means there is increased risk the lens power might be off compared to someone with normal vision. 

The lens can change position a bit in the first couple of months after surgery, which changes its effective power and can make your vision better or worse depending on which way it moves. They usually wait 3-4 weeks before prescribing glasses due to that, or less commonly if the vision still hasn't stabilized they'll wait   6-8 weeks or more. For most people though the change is minor, your vision a week after cataract surgery is what it will remain (aside from any healing problems like swelling).

 Any residual astigmatism also impacts quality of vision. Sometimes people don't have astigmatism before surgery because although their cornea has astigmatism, their natural lens has astigmatism in the opposite direction which balances it out. When the natural lens is removed and replaced with a spherical artifical lens, that leaves the cornea's astigmatism not balanced out anymore. 

The doctor should be able to tell you what your refraction is, your prescription, to tell how far off the lens power is. Numbers like "20/80" merely tell the quality of vision, they don't indicate what the actual refraction is.  The number of diopters in your prescription indicates at what distance your eye has its best focus.  You have a range of vision around its best focal point that is still useful, more going inwards from that point usually than going outwards.

The focal distance in centimeters= (100 / -diopter_refraction), so e.g. a refraction of -2 would indicate your eye focuses best at (100 / -2) = 50 centimeters.  Astigmatism complicates this a little bit, really the "spherical equivalent" would be used which factors in the astigmatism, but that is usually minor. (typically about half the astigmatism,paying attention to the sign, can be added to get the spherical equivalent, essentially the average focal distance for that eye).

Hi there. I am 49 and high myopia since childhood - about -10 in both eyes. Wear glasses or rgp contacts cos there's a bit of astigmatism without a problem, although I don't like wearing the contacts (which are set for monovision) for night driving, supermarket shopping or computer work as they make me feel a bit queasy. But they're fine for skiing or walking or cycling.

Now I have a bad cataract in the left eye and the start of one in the right. The NHS will operate on both eyes inserting a monofocal lense. Options are an equal -2 in each eye or - 0.5 in one and -1.5 in the other.

I asked if I could have a plain lens inserted so that my vision would remain the same. The consultant was amazed and asked why I would want to stay with such high short sightedness. I told him cos it was part of me and I don't mind wearing glasses. By doing this would I be eliminating any chance of correction going wrong?

What are your thoughts please?

It is unusual to wish to keep high myopia, but if you decide that is what you want then they should provide it, you are the one who has to live with it. Its usually only low myopes that get practical use out of having good intermediate vision or good typical reading distance vision who wish to retain it. They are used to being able to take off glasses to be able to perform some common tasks. Usually high myopes like I was find we wear correction 100% of the time since my best focal point was closer in than convenient reading distance and so we didn't get any benefit out of being that myopic.

If there is some activity where you like not needing to wear glasses where you focus a few inches in front of your face, then retaining high myopia might make sense (unless its not an activity you do often, in which case you could either get high + power contacts or glasses for that activity). Otherwise I guess one point is that if you merely like wearing glasses (which I'm uncertain of, given you do mention rgp contacts) then some people wear non prescription glasses for cosmetic reasons even if they have good vision. Or another option if you like the idea of being myopic would be to consider whether at least a more modereate level of myopia might be more useful, e.g. perhaps focused at reading distance, or one eye at intermediate walking-around distance and one eye at reading distance, to let you do household tasks and see the ground and walk around outside safely without correction (even if you can't see the street signs to see if you are walking  in the right direction :-) ). To me I liked the idea of not needing correction afterwards in part due to   safety considerations. While myopic I always had to worry about having an emergency pair of glasses around, and wondered how I'd function in a natural disaster or after an accident or fire if I were somehow without my glasse or contacts. Its useful to be able to have some useful level of functioning without correction, beyond merely being able to function a little in your own home to use the bathroom or get to your glasses/contacts.

Since I'm in the US I  haven't had reason to learn  the details of what  NHS covers. I assume if you insist they will leave you highly myopic. The only reason I can imagine they might not is that in theory its possible they might require correcting vision to a level where you have some useful level of vision without correction as a safety issue, viewing it as saving them money perhaps later on since if you can't see well at the distance your feet are at then when you are elderly you might be more likely to trip and fall and break a hip and cost them money. A -2 lens is focused at 50cm=19.69 inches so its further in than your feet, but at least the blur at your feet would be less than if you were highly myopic.

I can understand the issue about feeling your myopia is "part of you" in terms of it being part of your identity, and the fear it would seem odd not needing correction. It is a big change, though most discover it is a positive one. Even a bit over 2 years postop I still have moments where I'm amazed at how well I'm seeing the world without correction, it is definitely a shift to be someone who doesn't need correction, in my case I view it as a positive one, but someone might prefer not to tinker with what works for them I guess.

In one sense you wouldn't eliminate the chance of the correction going wrong in terms of the lens power not being exactly what they shoot for. If they shoot to make you -10 there is a chance  chance they might instead make you -9.5, -9, -10.5,-11, etc.  However  the issue is that unlike those who are looking for perfect distance vision without correction, where a difference of 1 diopter might be a problem, if your eyes are off by that much you may not in practical terms tell much off a difference.   A -10 eye has a  best focus at about 10cm= 3.94 inches, while a -9 eye has a best focus of  11.11 cm=4.38 inches and a -11 eye has a best focus of  9.1 cm  = 3.58 inches.  So if the correction doesn't hit your exact current level of myopia, its not clear if you'd in a practical sense notice.

Thanks for this. Your last comment is spot on. I think once you get over -4 or so everything is a blur anyway!

My thinking was as it's much more difficult to obtain the refraction aimed for in high myopes there is more chance of something going wrong. I'm really concerned to read some of the stories on here. It seems there's an element of luck involved!

The NHS service in the UK is amazing but they only offer a monofocal lense. If I go private and pay around £5000 I could have a Symfony multifocal lens in each eye which the consultant said would (could) give me excellent vision at all distances. However I believe the chance of haloes and glare especially in night driving increases with this lense which is a concern.

I used to wear same prescription contacts all day but they got changed to monovision lenses when I was about 45 to cater for the presbyopia. I don't like them much though and would prefer them to be the same prescription again and just wear readers on top for close work. So I feel I definitely want my eyes about the same with a difference of no more than .5.

Remind me please of the surgery you opted for and the specific lends inserted?

The  major issue with high myopes vs. others is the lens power selection, and they've gotten better at that over time so for most people the result is still very good (and if it isn't, then laser correction is an option,and laser fine tuning afterwards is sometimes bundled with a deal for a premium IOL).  High myopes have larger eyes so there may be some more risk of a toric lens rotating since its looser in the capsule (since IOLs are physically all the same size for every power), though it sounds like the risk may not be that much different. Other risks like retinal detachment  (usually at some point postop, perhaps a few years later even, not during the surgery itself) are very rare with modern surgical techniques, even if slightly increased.  I had a rare issue I'll get to below.

The most likely flawed result after cataract surgery  with a high myope is merely a slight  increased risk of needing to wear correction afterwards due to the lens power being off, or at least until a laser touchup if they go for one (and that the small laser tweaks required after surgery are safer than the larer corrections most people get with laser surgery, and that is also far better than it used to be).

I opted for the Symfony lens, implanted in both eyes early December 2014. The Symfony was the best choice for my needs, for those who want more near a trifocal may be a better bet (at the cost of not quite as good intermediate, and slightly higher  risk of halos&glare and reduced dim light vision since it splits the light more).  At my last eye check a couple of weeks ago I had 20/15 vision at distance (and it was easy to read the line, they didn't have a line below that, so it might be slightly better), at intermediate computer distance, 80cm, it was 20/20 (plus a bit). At near I've consistently tested 20/25 at my best near distance, where they give you a chart to hold where its easies to read. In this case they tested it at a fixed 40 centimeters, and they didn't have a 20/25 line, so I tested 20/30, but read some on the 20/20 line so it likely matches my prior tests of   20/25.

That  result is despite a slight glitch in the lens power on my left eye which wound up +0.5, slightly farsighted, which does reduce its near but my left makes up for it (so I hadn't bothered with a laser tweak).  My left has a trivial myopia, -0.25  sphere with -0.25 cylinder. I am one of the rare people that sees halos with the Symfony, but they are so mild/translucent that I see through/past them and haven't considered them a problem since my night vision is overall better than I can remember it being. I think that is partly since I actually notice less glare issues, bright headlights are less distracting so having halos around them that I see through is a tradeoff I don't mind. 

The nice thing about the Symfony is that due to its extended range of focus, even if the lens power were off and correction were worn, its likely that single vision glasses or contacts (rather than varifocal/progressive glasses or bifocals or multifocal contacts) would suffice.

Unfortunately there is no perfect IOL yet, there are always tradeoffs. Some people even have problematic halo or glare issues with a monofocal lens. Studies put the risk of problematic halo&glare issues with the Symfony as being comparable to monofocals, though not as low as the best monofocal. Unfortunately some rare people wind up being the "statistic" with halos they consider problematic, but the same is true of a monofocal, and a lens exchange is usually an option. I figured better vision for a few decades was worth the slight risk of needing a  lens exchange. Contrast sensitivty is comparable to a monofocal in most studies, though some suggest there might be a slight reduction. So vision in dim light, like reading a menu in a dimly lit restaurant,  might be slightly reduced from a monofocal, though in my case its definitely better than it was with multifocal contacts before I had my cataract.  Oddly someone here with the Crystalens seems to have noticeably worse dim light vision (we compared it in a well lighted room where we met and he held something to cast a shadow over the near reading chart, and it cut his vison by some lines, but not mine). That was  despite being about the same age and despite the Crystalens being a single focus lens, albeit one that may accommodate a bit.

 I  actually traveled to Europe to get the Symfony, and you could   get it far cheaper outside the UK.  The lens actually wasn't approved in the US at the time, our government is slower about approving things and so they stil haven't approved trifocals here. The only multifocal IOLs here were high add bifocals, and since intermediate distance is more important to me, and I may live with the results a few decades, I decided it was worth traveling. 

I considered going to the UK and checked on other countries, but I'd heard that those in the UK sometimes use the Czech Republic for medical tourism. I decided that as long as I was traveling, I could use a top surgeon there and still get it cheaper than the UK. Last I checked for someone a few months ago, depending on options like laser cataract surgery and lens choice, at various clinics in Prague now you can   get the treatment for $1200-$2000 per eye total paid out of pocket from a reputable surgeon (I'll let you do the currency conversion). Fortunately I had little astgimatism so I didn't need a toric lens. 

Did you ever try multifocal contacts? I liked them, which is part of why when my cataract appeared my initial assumption was that I'd go for a premium IOL. Unfortunately after people get cataracts it is hard to give multifocal contacts fair test if the cataract is interfering with vision. Their optics are a little different from premium IOLs, but at least it would give some sense of having vision corrected for multiple distances at once.  I discovered I liked multifocal contacts better than  monovision in part because I noticed that the world seemed more subtly more 3D since I was using both eyes. I hadn't noticed the reduction in stereovision with monovision while I had it, I think since the difference between the eyes only gradually increased each year (and I only extremely rarely wore glasses for a few minutes at home). 

The thing to remember is that there are > 20 million cataract surgeries worldwide each year, and the vast majority have great results. Unfortunately even if only a tiny percentage of those have problems, obviously *someone* winds up being the statistic and can give others a skewed perspective on the risks. Those who post are usually those who have problems (or occassionally some who researched things beforehand online and feel it appropriate to return the favor by posting information afterwards, who know it can be difficult sorting out options, especially for those of us a few decades younger than the typical  cataract patient since we expect to live with the result much longer and on average are more active). There are far fewer who get premium lenses, but they are often those more likely to have gotten them because they did net research and since they use the net they may be more likely to post.

For full disclosure, in terms of the existene of risks for high myopes, I had a very rare issue due to my high myopia (unrelated to the choice of IOL). Its extremely rare even for   high myopes,. Its   likely one out of tens of thousands or perhaps  rarer, surgeons didn't hazard a guess at how rare, most don't surgeons don't see it so I kept checking around trying to find an explanation for the symptom of flickering light when reading close up. Iridodonesis, the iris jiggling, can happen  after surgery to  some high myopes since an IOL is smaller than the natural lens, and the iris loses support and when the eye moves it can jiggle a bit, e.g. when the eyes are moving back and forth to read (not something that anyone looking at you would notice, it took getting a video of my eye while reading to discover it). That  is usually innocuous and doesn't cause issues. In rare cases, in those with light colored eyes, the stray light passing through the iris can be an issue if as in my case there are black striations in the iris mixed in with the blue, so as the iris moves the stray light varies. Its like a rotating fan blade blocking light part of the time causing a flickering effect. In my case it was only an issue with reading, and over time my brain has been learning to tune it out. (and its always been worse with close up reading than computer distance, and fortunately these days almost everything can be read online).  My risk may have been higher due to having  been younger than the typical cataract patient, so my retina is more sensitive to light  (including stray light) than someone of more typical cataract age.

It was when i visited the optician last July to enquire about bifocal contact lenses (cos I keep having to move my glasses down my nose to read) that a) she told me I wasn' suitable because they are soft lenses and I need RGP for astigmatism and b) she found the deterioration in the vision in my left eye and altho' she could see the beginnings of a cataract she didnt think that was enough to cause such a drop, so she referred me to an NHS consultant.  However, the wait was 5 months and thats when I decided to pay and get a private consultation as I wanted to be sure there was nothing else 'going on'.

So the private consultant said he could fix my eyes so I didn't need glasses at all but he didn't actually say which lens he would use, how my eyes would be set, what the risks of haloes would be (they weren't mentioned at all) and the rough cost he gave me turns out to be for a standard lense only so now the cost is £600 more per eye.  

I have an appt in 10 days with the NHS consultant who obviously has nothing to 'sell' and I want to know what he thinks he could achieve with a monofocal lens which is all that will be available to him on the NHS. The private guy actually said I shouldn't bother to see the NHS guy and should cancel my appt which I thought wasn't right - I am entitled to have a consultation with the consultant in charge of my NHS surgery, should I go down that route.

I like what I know ... i have an old phone and an old car, both of which work perfectly well.  I don't like change and it would be a disaster not to be able to work (computer) or drive (live in a village).  At the mo I can type this, look at the TV or check my phone all with the same pair of specs.  If I go for a plain lense I will be retaining the status quo of 45 years and if they get it wrong by an optre or half it won't matter since like you say -9 or -11 is no different to -10 for me!

Saying that, there is a suggestion of going for -2 in each eye, meaning I can see a lot more without my specs (I had never thought about the safety aspect before you mentioned it) and will still need specs (but thinner and cheaper) and can still wear contact lenses perhaps with glasses over the top for close work.  Your thoughts please?  (PS  It's not the thought of having to pay for an op that I could have for free, it's the thought that I just want the cataract sorted but never wanted to have my vision interfered with!

Is your vision degraded enough due to the cataract that the NHS will cover it now? In most places government or insurance only covers it when it degrades vision to 20/40 best corrected, though some are starting to consider other issue like degraded night vision and be more flexible about covering surgery.

re: "At the mo I can type this, look at the TV or check my phone all with the same pair of specs.  If I go for a plain lense I will be retaining the status quo of 45 years and"

The problem is that it won't be the status quo, it is like the level of presbyopia an elderly patient has in terms  of the range of vision out of each eye.Usually people have decades to adapt to a slow degradation in the amount of near vision they have, higher adds gradually over time in their glasses.  The range of vision people get with a monofocal varies greatly, but the typical thing I've read from doctors is that with a monofocal set for distance (or single vision glasses correcting a monofocal to distance)  that things will get blurry from 6 feet inwards. I saw a recent post from someone with a monofocal where it was 10 feet where things got blurry, though some tiny minority of lucky  people get good intermediate vision with a monofocal, it isn't to be expected. The lower range of vision means some people find their distance glasses won't work to see intermediate at computer distance, and that their intermediate distance computer glasses don't work for near reading distance. 

So most people with a monofocal  even for driving might want bifocal/trifocal glasses or varifocals/progressives in order to be able to see distance and maps/phone/stereo. Unfortunately varifocals/progressives tend to not be as easy to adapt to with the high adds required since  there is a larger range of focal points covered over the same space on the glasses so a small eye movement changes focus to a greater degree.

 I tend to describe the Symfony as like early presbyopia, where most of the time I don't need correction to see near, but I'm aware that my very near is blurry (as yours would be now when wearing distance correction). So it is like rolling back a little bit of time for someone your age, vs. skipping ahead many years with a monofocal IOl to final state presbyopia.

I rarely wore glassses rather than contacts, and even with the level of presbyopia at 49 when I tried varifocals/progressives (fyi, I keep using both terms since the UK and US use diferent terms and not everyone is aware of that) I didn't like them, I much preferred contacts. Of course its also possible to do multifocal contacts with a monofocal IOL, though the  multifocal vision may not be the same quality as using a multifocal IOL (or extended depth of focus as with the Symfony, which is different, even if similar). 

I didn't like the idea of having such a small range of focus, which is why I figured I'd go for a trifocal, and then decided on the Symfony after that came out.  I had figured if they didn't get the lens power right that I'd get a laser tweak, but that in the meantime even if needed to wear correction that the Symfony would be more useful than a monofocal since I could wear single vision correction most likely, or that if I needed them that varifocals/progressives would work  better since they'd need a lower add. 

Yup, the glasses with a low prescription are much cheaper/thinner, these days you can get dirt cheap ones online from places like SelectSpecs and ZenniOptical if you can use a cheaper lens material.  I don't need prescription glasses for distance obviously, my distance vision is better than I ever experienced with glasses or contacts as far as I can remember,  but   I wanted new sunglasses with a lighter tint and discovered  I could get dirt cheap prescription ones made with whatever light transmission I want so  I'm waiting on some now since I'm curious if I'll notice the difference.

re: "have an old phone and an old car"

That is understandable, if something works then many people see no reason to tinker with it. I do that in some parts of life, though in others I'm more a typical technophile early adopter, often working at the bleeding edge of computer technology.

re: "didn't think that was enough to cause such a drop"

Oddly I had a similar experience at the same age, it may be partly at age 49 they assume it isn't a cataract issue. I never had enough astigmatism to worry about toric contacts in the past.  I was trying a new model of contacts and when I came back for a followup since they weren't working well, the optometrist saw the problem was  my astigmatism had increased, and she was puzzled about the problem, since she didn't think the slight changes in the lens were enough to even label a cataract. She described it as "trace nuclear sclerotic changes"  in a referal to an ophthalmologist who diagnosed the problem as a cataract, which eventually the optometrist was able to see as it got worse. In the course of 3.5 months my astigmatism in the one problem eye had gone  from -0.75 to -4, and best corrected vision dropped from 20/25 to 20/60 and the optometrist  was stumped and finally gave up and referred me to an MD to diagnose it. Usually cataracts don't appear and worsen that quickly (at least nuclear ones that don't seem to be related to any trauma or medication side effect) or impact refraction that much. (that eye later saw astigmatism subside, but  increased from -9.5D sphere to -19 before surgery).

Actually there are toric  multifocal contacts that correcet for astigmatism in both soft and RGP models.

dear Jenny 

It would be most unusual to aim for a post-operative target of high myopia and as which you have! 

the options the NHS surgeon has suggested to you ie  equal -2 in each eye or - 0.5 in one and -1.5 in the other seem spot on to me, and especially as you say you do not minf wearing spectacles or indeed contacts 

COI: I am an NHS cataract surgeon and with a professional interest on the insertion of 'wrong IOLs' 

I no longer implant multifical IOLs as too many patients report haloes etc whereas such matters are almost unknown with correctly implanted monofocal IOLs 

Hi Simon,  I had noted that you were part of this forum and wondered if you were watching my notes to softwaredev.  Needless to say your last comment caught my eye ...  Can I ask which part of the UK you are in?  I am in the South West/Midlands.

I am seeing the NHS consultant that I am 'under' the week after next - I have specifically asked to meet him before the op in early April to be very clear about the surgery. 

i have made some decisions already:

not to go for a multifocal.

i want my eyes to be set the same (cos I don't get on with my monofocal contacts).

The third decision is to see if i can just have the worst eye operated on and manage with a contact lense in the other eye for as long as possible - that would be better than rushing to get the 2nd eye done within a few months as has been suggested in the pre-op assessment, when the cataract really isn't that bad yet. (thus lowering the risk of a retinal detachment in BOTH eyes)

Once the operated on eye has settled surely i can get a new lense in my existing glasses for that eye (to accommodate the -2) and a new contact lense?  

Or would I need readers / bifocals for close work?!

PS  It had occurred to me that multifocal IOL's were only approved in the UK in 2014 and so there is no long-term data yet on their use, whereas monofocal lenses have been used for decades by the NHS.  Sometimes it's better to stick with the tried and tested ... 

dear Jenny 

i agree that not having cataract surgery soon on the fellow eye is a good plan.

you can continue to wear the contact lense in the good eye only and then just get a low spectacle correction to wear over both eyes  and which may be circa -1.5 for distance in the eye with new IOL

The reason why the surgeon may be scheduling you for both eyes in quick succession is that few patients will do the above and most patients cannot tolerate a significant imbalance in spectacle lens powers between their two eyes (known as anisometropia) 

multifocal IOLs  were in use in the UK since circa 1990.

Severe of the IOL brands used in early days ended up causing 'issues'

Secondly, existing contact on right eye, new contact to combat -2 in the left eye, yes?  Will I need second pair of reading glasses to put on over th contacts?

What i was alluding to  was you could perhaps wear spectacles of circa minus 1.5 in both eyes and that such spectacles be worn over the contact lens in the non operated eye

You need to speak to the surgeon and also perhaps disregard a lot of the comments on this website !

I misunderstood your last message, Simon - should have read it twice before replying!  You mean to wear the contact lense in the good eye plus glasses for a low prescription over the top - wearing them all the time to correct the -2 in the bad eye (as it doesn't work having 2 very different glasses lense prescriptions, as you said)  Would it be a plain lense in the right eye then? (as the contact has already corrected the vision)

Got it now!  One more thiing - if I wanted to wear just my contacts sometime, e.e. to go skiing (!), would i have one to correct the -2 vision in the left eye?

I am much clearer now on what's what and how this could work and feel much happier and more prepared for my chat with the NHS chap in 10 days time.  Really appreciate your advice, Simon.

yes for sking you would wear -2diopter contact lens in the eye which has had IOL implant and you existing contact lens in the fellow eye. You could also cobsider carrying a pair of off the shelf 'ready readers' (circa plus 2.5 diopters)  to read maps etc while sking or for reading the menu in the ski resort 

I expect you will wish to request lens exchange (aka cataract) surgery in the fellow right eye in due course and once you experience the massive benifit you willl have had from the cataract removal in left eye

Yup, it was the Symfony that was just approved in the UK (and Europe) in 2014, and the US in 2016. Multifocals have been used for quite a while, however they have been improved quite a bit over the years in terms of a reduction in risk of halos&glare. Unfortunately some surgeons used the early generation multifocals and encountered too many problem patients, and then haven't given newer multifocal IOLs a chance since their interest is in what is easiest for them, rather than what is best for the patient. (though admittedly on the flip side there is some incentive for some docs to get people to pay more for a premium IOL).

 Monofocal patients might not have as much useful visual range as they might have with a premium lens, but they don't have anything to compare it to so they don't complain so the doctor doesn't need to deal with it like they neeed to with a patient who has problem halos with a multifocal.  

To me the certainty that a monofocal would make functioning more difficult for any remaining decades of life  due to a lower range of vision outweighted a slight risk of problems with a premium len. 

In terms of "long term data", in most of the ways that would matter over the "long term" the multifocal  lenses (and the new category of extended depth of focus lenses) are the same as monofocal lenses. For instance the Tecnis multifocals and the Tecnis Symfony are made from the same material as the Tecnis monofocal and have the exact same overall size and shape, it is merely the optics that are different.  By analogy to eyeglasses, its like having the same eyeglass frame and using the same material for the lens that goes in them, but merely griding the lens differently. Any medical issues related to the material and its biocompatibility or issues of PCO or edge relfections or  the physical stability and placement of the lens would be exactly the same. 

The major issue is the difference in optics, where neuroadaptation means the results get better over time, so long term data isn't really a concern. e.g. the incidence of halos will go down over time. So long term results would be better.

The only issue regarding long term use that is imporant to consider would be the interaction of a premium lens with other eye problems that might arise over time. That   is a risk some people might not think of. Some people who have other eye problems, in addition to a cataract, aren't considered candidates for multifocals due to those other issues not playing well with multifocals. However its always possible that you might develop that eye problem in the future after you've had a multifocal implanted.

In my case I knew that was a possibility, but that the risk was low. If I ever developed some other eye problem that didn't play well with a premium IOL then I could get a lens exchange to a monofocal. The high probability of having more useful vision for a few decades was worth the slight risk of needing an exchange. Also fortunately the Symfony seems to be more tolerant of other eye problems than multifocals, though that is an area where there isn't much data yet because doctors are cautious about implanting a non-monofocal in someone with other eye issues. Each person needs to make their own risk assessment though.

Ideally decisions should be based on knowing what the data shows. Unfortunately many doctors base their decisions based on their personal anecdotal experience with patients, rather than what larger studies say which may be more statistically representative of likely outcomes.  

re: "You need to speak to the surgeon and also perhaps disregard a lot of the comments on this website !"

Unfortunately there are some problematic comments on this site from patients who haven't educated themselves on issues, so its worth suggesting people exercise appropriate caution. However I'd also suggest that the most productive response to such comments from someone knowledgeable is to post specific critiques of flawed comments. Especially since in the real world busy  doctor's don't always educate themselves about a particular topic if they don't need to. e.g. many surgeons are focused on medicine rather than optics and don't spend time reading through the data from various IOL studies (whereas others do, I corresponded with a surgeon prior to getting the Symfony who was researching it at the same time  and who passed along what might be the patent for the tecnhology that went into the detailed physics and math behind its diffractive optics).

re: "I no longer implant multifical IOLs as too many patients report haloes etc whereas such matters are almost unknown with correctly implanted monofocal IOLs"

The idea they are "almost unknown" is questionable, even if the risk is lower than with multifocals. There is no lens yet that doesn't give someone halos.  Studies for approval of multifocals by the US FDA compare them to a monofcal control lens. In this case the April 2015 approval of the Alcon Restor +2.5 lens includes a comparision with an Alcon monofocal (one of the most widely used monofocal lenses, and possibly the most widely used though I don't have statistic). Since this site moderates links, google this:

"ACRYSOF IQ RESTOR +2.5 D MULTIFOCAL INTRAOCULAR LENS" 15M-1325

The page that shows up has a link for the summary of safety and effectiveness data. In table 12, the monofocal result shows mild halos: 26.9%, moderate 7.5% and severe 3.8%

Unfortunately I haven't seen a head to head comparision between the Symfony and an Alcon monofocal, and I'm not sure without looking further if those were directed or non-directed responses to know what data to compare it to. Comparing data from different studies is somewhat problematic since they can ask questions differently or have different patient demographics, so you just get some general sense of the general magnitude of results.  Googling "High rates of spectacle independence, patient satisfaction seen with Symfony IOL" shows a summary of multiple studies of the Symfony showing low rates of dysphotopsias that appear to be in the same general range as monofocals, if perhaps a bit higher than some, not by much.  The studies show it not doing as well as the Tecnis monofocal control, so its not the same as the best monofocals perhaps but comparable to others, so I'd be curious how it would do in a direct head to head comparision with an Alcon monofocal.

re: "I no longer implant multifical IOLs "

I should note that I hope this merely means you educate patients on the pros and cons in as unbiased a manner as possible, and then refer those patients who wish a multifocal to other surgeons. Some patients when presented with the pros and cons will chose to use multifocals, just as some surgeons consider them to be the best choice for many patients. If no patient opts to leave and get a multifocal elsewhere, that would suggest a biased presentation of the pros and cons . It is rational if some surgeons choose not to risk needing to deal with patient problems to make their jobs easier, and refer patients elsewhere to surgeons who have more patience for giving patients what they want even if it means dealing with some problems.

Unfortunately I get the impression most surgeons wish to keep their patients and instead would be more apt to push monofocals and not let their patients get a fair hearing of the pros and cons of multifocals, rather than merely their personal biases. Some patients aren't going to carefully weigh the options and go with what their surgeon recommends. Some patients unfortunately won't do a good job of evaluating the pros and cons, but many  are a better judge of their personal needs and risk tolerance than the surgeon could be.