Monofocal IOL distance

Ron's advice is very good and well-written. Not to confuse, but to add an option: Johnson and Johnson has a lens called Eyehance. This lens is technically a monofocal and thus covered by many US health insurance policies, yet it has the promise of a bit more near vision. Worth researching. As Ron noted some clinics use only one brand, mine did not use JandJ, so even though I researched the Eyehance, I could not get it with my doctor. I opted for Alcon's VIvity, which is an extended depth of field lens, thus costs a premium. I am not sure it is way better than the Eyehance, but since it is classified as a premium lens, it costs more, about $2500 per eye. I am satisfied with my lenses , but I do need readers for the IPad and books. Vision is crystal clear at arm's length and beyond. Well,honestly , 20/25. I can drive fine night or day.

You are very fortunate that you have a year to research your options. You will find lots of good advice here and on Youtube. Best of luck.

Yes, the J&J Eyhance is an option, and while it is not technically an extended depth of field (EDOF) lens, it really is not a monofocal either. It has a mild amount of EDOF which I believe they achieve by varying the power of the lens from the middle out to the edge. So instead of a single fixed power it varies. For that reason it will not have as sharp of a focus as a true aspherical monofocal lens. But, for those wanting a bit closer vision at a small loss in vision quality it can be an option.

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The industry has come up with a minimum standard of extended depth of focus to be called an EDOF, and the Eyhance falls just short of that standard. Nominally the Eyhance provides about 0.5 D extra depth of vision, while the Vivity does about 0.75 D extra.

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I suspect how this works out for cost coverage by private insurance or public healthcare will depend on the company and the jurisdiction. The Clareon is a pure monofocal lens and is just made of a slightly different material than the AcrySof IQ lenses. But in Alberta, Canada our public healthcare will not cover the extra cost of it, which appears to be $300 per lens over the AcrySof IQ. Things may be very different in the US and even from province to province in Canada... And the UK different again, I'm sure.

Thankyou for your detailed answer , very useful, l am in AUstralia so l dont know if we have those lenses . In Australia you have the choice of the public system which is free but you dont get to choose the lens or surgeon , you just get a standard mono focal lens. The other choice is you can go with the private system which can cost from $3,000 to $7,000 but you can choose a premium lens and your surgeon . l am thinking about saving up the money for private so l can choose a better lens. Should l ask for an Asperic lens and not a speric lens , l think you said Asperic has better vision quality. l dont really like the idea of mono vision with one eye near the other far, l think l prefer glasses for close up. Also can you give any advice on how to choose the best surgeon , l live in a small city where l only have the choice of two surgeons , my GP said they are both good. l dont know if l should go with one of them or travel a few hours to a large city where l would have hundreds to choose from?

Keep in mind that IOLs that are referred to as "premium" lenses are premium in price, not in vision quality. You will get the highest quality vision with a basic aspherical monofocal lens. What you get for a premium price is an extended depth of focus. But they come with compromises in vision quality. The most common issues are flare and halos around point sources of light at night (like car headlights, or street lights), or a combination of both commonly called spiderwebs. The closer the focus that they provide the more likely you are to have these optical side effects. Some people are OK with these side effects, and significant extra costs, and others end up having them replaced (explanted) which is a risky procedure that you really want to avoid.

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If you go to a private clinic, I think you may find they will want to push you toward multifocal or extended depth of focus lenses as that is where the big bucks are for them. Examples would be:

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J&J - Synergy, Symphony, and possibly Eyhance

Alcon - Panoptix, and Vivity

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I think I would start by talking to your optometrist and asking them what lenses are available through the public health system so you know what your choices may be. It may not be the same with each surgeon. The optometrist should also be able to advise you on how experienced your local surgeons are. It is a very common procedure and your local surgeon may do hundreds if not thousands a year. The surgeon that myself and my wife went to does something like 25 surgeries per day.

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If you can get the names of the surgeons you could also try contacting their office to determine what lenses they can do. They should answer simple questions like that.

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You can also ask your optometrist about monovision as a trial with contacts. You might like it. I am currently simulating it with one IOL and one contact, and like it a lot. Optometrists should have access to free samples of contacts that you may be able to try at no cost. I also have progressive eyeglasses which do give me somewhat crisper vision, and closer vision, but now that I have gone about a year free of eyeglasses I only wear the progressives when I need extra good vision, or to give my eye a break from the contact.

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Hope that helps some,

Thanks , if l go with monofocal in both eyes for distance will watching TV from 6 feet away be totally clear and sharp without glasses? Also if l hook up my laptop to a large 32 inch monitor so the text is large and its a couple feet away do you think l would be able to read the screen without glasses? The surgeon l think will go with has ten years experience doing cataract surgery, based on that should l go with him or should l do more research into him before l decide to go with him?

Yes, for sure TV 6 feet away will be very clear with distance monofocal lenses. With the computer monitor two feet away it is most likely to be quite clear too if the text is large enough to be seen that far away.

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As far as surgeon experience if you have an optometrist that you trust, I would ask their opinion of who is best. I did a quick search on what is covered in Australia by public healthcare. It seems to be a real can of worms, but one site I saw indicated that the medicare system will cover the cost of getting a second opinion. So if there are two surgeons in your area, you should be able to see them both and compare what they say, and what they offer for lenses.

Ron,

I oiginally posted a few weeks ago. Still weighing my options for cataract surgery. I read where you said to John20510 that setting the IOL for distance is the "safest choice." Why is that? Is it easier for the surgeon to aim for distance rather than intermediate? I am a high myope and had read Bookwomans experience with intermediate vision and it sounded good to me, althought I do have more astigmatism than she does. Mine is 2D per tomography. I can't afford a toric. I do not want to do mini-monovision.

Also, I read what you said about the J &J Tecnis 1 non toric monofocal vs the J&J Eyhance non toric monofocal. I recently went to a new optician to have my eyeglasses adjusted. He said that because of the way the way the Eyhance is designed it makes it more difficult to get an accurate eyeglasses prescription for astigmatism compared to the Tecnis 1. He tried to explain it to me, but I couldn't understand his technical language. Do you know what he meant by that?

Thanks.

I probably should have said that setting the monofocal for distance is the standard choice. If distance is important to you then getting both eyes targeted for distance is likely also the safest way to go as you double the odds of one eye or the other being really good.

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There is nothing risky about going for reading distance or an intermediate distance. You get what you get, and probably there may be a little more forgiveness as eyeglasses are going to be required and will make up for any residual error.

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I am not sure what the optician would be talking about. It should be possible to prescribe eyeglasses for the Eyhance to correct astigmatism. The only issue I can think of is that the Eyhance varies the power of the lens with the radius of the lens. The perimeter of the lens has a slightly different power than the middle of the lens. While this provides a wider range of focus it also gives a less sharp image. And because of the varying power in the lens and eyeglass lens cannot correct for that. All it can do is provide the best average correction. Compared to a standard aspheric Tecnis IOL the resulting image is not going to be as sharp. That is kind of the price of an EDOF lens. If you are going to wear glasses and you want the sharpest vision I would stick with a standard aspheric monofocal. And since you are not correcting astigmatism your vision is not going to be the greatest without eyeglasses anyway. An EDOF to go without glasses probably only makes sense when you also correct astigmatism with a toric.

I think in your case where you are not doing a toric IOL and your astigmatism is pretty significant at 2.0 D, I would count on wearing progressives for the best vision. If you set the power to leave you myopic to read without glasses your vision is not going to be great, even with readers. And, your glasses will be thinnest and lightest if you fully correct for distance and only get a +2.5 Add for reading. If you leave yourself at -2.5 D your prescription glasses are going to start to become thicker and heavier again.

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Based on experience -D astigmatism can help you read some but it gives a poor image quality.

So Ron,

Are you saying that I would get the best progressive eyeglasses and overall vision if I had my monofocal set for distance rather than intermediate? I've always been able to see my watch, hands, cellphone without eyeglasses. I might feel strange losing that close vision. But I do want the best overall vision and you think setting the IOL for distance would be better for that goal?

No, that was not what I intended to say. I don't think the quality of vision WITH progressive eyeglasses would be significantly affected with choosing an intermediate IOL compared to a distance. The eyeglasses should be able to correct effectively either way. If you were to choose an Eyhance then the eyeglass vision may be compromised slightly due to the defocus characteristics of the Eyhance EDOF. Your progressive glasses are likely to be thicker and heavier if you choose an intermediate IOL though. But, that should not reduce the vision quality.

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What you have to consider is the vision you get without eyeglasses on. Without a toric IOL it will be compromised somewhat. If you go for intermediate then of course it will be better at intermediate compared to distance, even though astigmatism will be degrading it somewhat.

Your progressive glasses are likely to be thicker and heavier if you choose an intermediate IOL though.

My -2 and -2.5 progressive lenses are noticeably thinner, lighter (and much less expensive!) than my previous -8 high index lenses. They'd no doubt be even thinner if I had distance IOLs, but in comparison with my old prescription it's a distinction without much of a difference, IMO.

Thanks Ron for your detailed reply. And thank you Bookwoman for your input as well.

For sure -8.0 D lenses would be thick at the edges.

Carol,

I too am myopic and most likely will choose near vision lenses after cataract surgery because that is the way I'm use to seeing. Can you explain why you would choose intermediate distance over near? Would intermediate be best for looking at a computer? Seems to me by choosing intermediate you will have worse vision without glasses for both near and distance? What would your ideal best near vision be without glasses?

Dave,

Well, that's what my opthalmologist recommended, although the choice was left up to me. Bookwoman's posts influenced me a lot. She knows way more about intermediate vision than I do. Maybe she can chime in here. Intermediate seems to be a good compromise between near and distance, especially for computer use. That said, a friend of mine in another state told me that a cataract surgeon recently told her that is harder for the surgeon to get accurate results when aiming for distance. She lives in a large city, so she will other opinions.

Carol,

My opthalmologist told me that he has had good results with patients with similar prescription as me (-4.50, -4.75 and astigmatism) by targeting -2.0 after cataract surgery. I assumed -2.0 was considered near vision but maybe it's intermediate. I intend to wear progressives most of the day and hopefully when I'm winding down and reading and surfing on my phone before bed I could do it without my glasses. I'll probably get a pair of near distance single vision glasses as well. Ron and Bookwoman as well as others have a wealth of knowledge on this site. I am just starting to learn about various target options after cataract surgery.

The distance of best focus can be calculated by dividing 1 meter by the target diopters. A target of -2.0 would have an optimal vision point of 1/2 a meter, or about 19".

I don't know if one would call -2 near or intermediate. With my -2 and -2.5 eyes I see perfectly from about 12 - 18", and serviceably quite a bit beyond that. Perhaps -3 is considered 'truly' near?

In any event, I do think -2 is a good power for those of us who like myopia, particularly if you're going to wear progressive glasses.

Bookwoman and Ron you both say that you can see well over a range of distance with your near/intermediate vision. However, I read that there's no accommodation

with monofocal lenses. I also read somewhere that a little astigmatism allows someone to have a little better field of vision or depth of field. Do accommodation, field of vision, and depth of field all mean the same thing? Am I wrong to think that all of these terms mean the range of distance someone can see like Bookwoman and Ron can see between x and y inches with their near/intermediate vision?

The answer to your question is in the defocus curve for the lens. Have a look at this article:

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Review of Ophthalmology 15 APRIL 2021 IOL Review: 2021 Newcomers

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And more specifically look at the blue defocus curve graph for the Tecnis lens. It shows what the vision will be at the peak of the lens. In this graph at the 0.0 Diopter position. A 0 D is infinity or full distance. The LogMAR (vision quality) is at a maximum. Then as you go off to the right the LogMAR goes down. A value of 0.2 is considered to be the limit of good vision. The standard Tecnis monofocal hits this value at about -1.0 D. If you divide 1 meter by 1 D you get 1 meter for distance. In other words a standard monofocal is good down to about 1 meter.

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Next if you select a power of the IOL so it is optimized at -2.0 D the whole blue curve slides over to the right so the peak is now at -2.0 D. This corresponds to a distance of 1 meter divided by 2 or half a meter. But, on each side of this peak the vision does not drop off the cliff. It goes down gradually. It takes some mental gymnastics, but while the curve peaks at -2.0 D it is still good at -3.0 D or 1/3 meter or a foot.

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In the other direction you get to the good vision point at -1.0 D or 1 meter. In other words with a standard monofocal that leaves you at -2.0 D myopic, you should have good vision from about 3 feet down to 1 foot, with the best vision at about 1.5 feet or so.

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But, it is not quite that simple. If you notice on the blue line on the graph there are error bars that go up and down. That is the range of actual participants vision in a trial that the line is based on. Some people see better and some see worse due to a variety of factors. For example while the curve predicts a monofocal set for distance is only going to give good vision down to three feet, I feel I can see to a bit less than 2 feet.

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Hope that helps more than it confuses....

Ron this was very very informative and helpful! Thank you so much!

Ron,

As much as you know about optical physics, I think you could probably go to work for an IOL manufacturer and help design lenses. I didn't go to college and barely made it through Algebra 1 in high school. I have no idea what -this or +that or diopeters mean. I don't even remember the metric system anymore. But a number of people on this site seem to understand these terms. I am fairly well-informed on diseases and medications, but I find opthalmic refraction quite hard to understand. Is there any website thar explains it simply? Thanks for all you do here,

A defocus curve is not the easiest to understand. They are developed using people that have an IOL implanted. First they are corrected for the best distance vision essentially like getting fitted for glasses. Then various power lenses are stacked on top of this corrected vision. For example lenses of -1 D, -2 D, etc are tried and then the vision tested. This measures how well you can see when off the peak focus power is applied. This is why the curves peak at 0.0 D and then drop in both directions as these trial lenses are added.

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Here is a title of an article that is somewhat dated so the lenses discussed are not the most current ones, but the theory is the same.

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CRSToday NOV 2010 Get to Know the Defocus Curve