Whats the differences between EDOF and mulitfocal

Well it is more complicated than just that as there is diffractive and refractive IOLs and now premium refractive IOLs that fall into the EDOF category.

First, let’s discuss diffractive IOLs.

One of my IOLs is a Tecnis MF. It has 2 distinct foci. So it splits the light for distance and close. Different MFs set different close foci points. And, in general, the closer the foci point the larger the halos. So your best vision would be at those foci points with vision getting worse as you move away from those points. So when deciding you need to think about what close vision distance is most important to you.

Later came trifocals that split the light into 3 distinct foci; distance, intermittent, and close. Again different Trifocals can use different foci points.

The best know EDOF in the US is the Tecnis Symphony. It has one elongated focal areas giving an extended depth of focus. It gives about 1.5 D of EDOF. So the goal was to get distance and better intermittent and close vision than a monofocal and simultaneously do this with less dysphotopsias than a traditional diffractive IOL. As far as the latter goes I am not sure it succeeded as there are many complaints of dysphotopsias associated with diffractive EDOF IOLs.

Then there is the Synergy, I have it implanted in my 2nd eye, and it combines EDOF with MF. It has the ability to provide one with great overall vision acuity from distance to close, but also IMHO the highest risk of all the IOLs. Even missing the refractive mark by too much can cause problems.

Now there are these NEW refractive EDOF IOLS (sometimes called Enhanced Monofocals) such as Tecnis Eyhance (does not even meet EDOF requirements), Alcon Vivity, and RayOne EMV. The goal of these IOLs was to give monofocal like vision quality and yet provide just a little bit of EDOF. I am talking just a little bit; like gaining a line of vision. But I argue everything comes at a cost and it has been shown that at least the Vivity comes at the cost of Contrast Sensitivity.

So my first advice is to find a top Ophthalmologist. If located in the US, look at US News Report for top Ophthalmologist. Maybe you will luck out and one of the ones listed will be near you.

Also start researching the different IOLs and learn there tradeoffs. All current, IOLs come with tradeoffs and you have to decide which tradeoff you can best live with.

Another idea is you can look and see if you can get into the clinical trials of the Juvene IOL. It is a revolutionary adaptive IOL. Have to have the guts to be such an early adapter.

Also there is the option of monovision, but Ron is the expert there so I will let him comment on that one.

And I should not leave out the Light Adjustable IOL. Another IOL to research.

By the way if you scroll through all the threads, all of these IOLs have been discussed at one point or another.

Thanks , l dont really mind glasses for reading close up, what l want is intermediate and distance without glasses and the highest quality possible, For example l dont mind wearing glasses to read the recipe book but l dont want to need glasses to make the meal. The most important to me would be excellent distance vision outdoors and driving and watching TV . l'm worried if l go with trifocal or EDOF the contrast and vision quality wont be very good and theres more risk of side effects or problems if the surgeon does'nt get it totally right, l guess what l want is the monofocal vision quality and sharpness with some intermediate to perhaps read my mobile phone if l stretch it out to arms lenght without glasses. The Tecnis Eyhance monofocal looks interesting. l am in Australia , l dont know all the lens options we have here

Hi @john20510,

You can read my recent posts about the Sympfony/Synergy combination. I am very happy with the outcome with these. I see well at all distances (20/15 far and 20/20 up close). Intermediate (not measured) seems best just from my own perception.

Good luck to you 😃

Hi John - good you have time to look into your options before needing cataract surgery. At 53 I was diagnosed with cataracts and needed surgery - no time yo look into it much. vision was poor - couldn't even read big E on eye chart. I did have a few months due to Canada's wait list for surgery and thankfully stumbled on these forums which were a tremendous help and support.

Younger you are the more compromise you must make. As my surgeon put it - in your 70s or 80s one gains something lost but when you are younger still working etc you have to decide what to give up. Personality plays a factor - more type A or perfectionist you are the less tolerant one may be of trade-offs with premium IOLs.

Myself given I work with a laptop most of my day - work with excel a lot - I wanted to be able to see that well. Was concerned about progressive lenses as I was just starting to need them and was having a hard time adjusting when cataracts hit. It was suspected my long term use of steriod creams were a contributing factor to my having this type of early cataracts.

I chose the EDOF Symfony lenses both eyes. I was surprised by how much near vision I got with these. I rarely need glasses - just for small print like pill bottles. There is a slight reduction in contrast sensitivity so good lighting needed for reading. In a dimly lit restaurant I use my flashlight feature on my iphone - although since pandemic hardly eat in those anymore - lol. Seriously though I can count number of times in last 3 years I wore glasses on one hand.

Trade-off and there is one is night vision. I see huge concentric circles around certain light sources night. IE red traffic lights - as I get nearer to them the circles get smaller and smaller till they disappear. I do not have that issue at night in my home with lights. I did have a lot of glare too till that settled down after a few months. I think that could be worse if the refraction target was missed. If I drove for a living or were a pilot this would not be a lens I'd choose.

each eye is different too and I think some people get better near vision based on their pupil size etc. Younger people have pupils that expand more and could potentially cause additional issues with them dilating beyond IOL (most if not all are a standard 6mm).

Wishing you well and it is really great you have this time to weigh your options.

I think the simple answer to your question is that an EDOF stretches the distance that a reasonably clear image can be seen. Instead of a sharp focus like a monofocal, image quality is compromised for an extended stretched out distance. And a MF lens splits the light and provides better vision at two or three distances. Since there is less than all the light used at each distance this compromises vision quality too. In my opinion both of these methods compromise image quality and contrast sensitivity. In simple terms instead of seeing a sharp single image you are seeing multiple images or ghost images around the main image. Your brain tries to ignore that, but since it is not a single sharp image there is a loss of contrast.

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Google the fairly recent article listed below. In particular pay attention to the graph that shows the vision quality at various distances (Defocus Curve). The bottom scale is in diopters but can be converted to distance by dividing 1 meter by the diopter number. Diopter of -1 is 1 meter away. A diopter of -3 is 1/3 meter or about a foot away. On the vertical scale you can see the vision quality. The 0.2 logMAR is considered to be good vision (20/32), and when you drop below that vision is being noticeably compromised. A pure monofocal hits this limit at 1 meter, while the Synergy hits it at about 30 cm or a little under a foot.

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There is one issue with this graph. I don't believe the Vivity curve. It seems to be more optimistic than what Alcon reports in their technical documents. I would suggest that a more realistic intersection point of 0.2 LogMAR for the Vivity is at -1.75 D, or 57 cm, or 22". The Eyhance is not shown on this graph but it hits the 0.2 LogMar at about 1.3 D. What is worthwhile noting from these curves is that a monofocal set for distance, does not drop off a cliff as you go closer. The monofocal hits the 0.2 limit at a diopter of -1 which is one meter or 3 feet. So when you say you want distance and intermediate, if you define intermediate as 3 feet then a basic monofocal will do it. And the other important thing is that these curves are an average of what real eyes get. Some will do better and some will do worse. I have a monofocal and I don't know what LogMAR it is, but I can read text on my computer screen at about 18-20" or so. It is not super crisp, but I can read it.

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Optometry Times A guide to the latest presbyopia-correcting IOLs October 27, 2021 Tracy Schroeder Swartz, OD, MS, FAAO

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On the monovision, since you still have good vision, I think you would be doing yourself a disservice by not trying simulated monovision with contacts. It is easy to do and try different amounts with contacts to see what you like or if you like it at all. As a simple example if you have a correction refraction for eyeglasses of -4.0 D in both eyes, you would determine which eye is dominant, and use a -4.0 D contact in that eye to correct fully for distance. Then in your dominant eye you would under correct it by 1.25 to 1.5 D. Which in the example would mean trying contacts of -2.75 D and -2.5 D. The idea is that you don't need sharp vision in both eyes to see a sharp image when you have both eyes open. Your brain will pick the best one. As you get closer and closer to an object your brain will switch from using the dominant eye, to both eyes, and to the non dominant eye. I am half way down that path now with one eye having an IOL for distance, and a contact in the other eye to give me -1.25 myopia or under correction. I like it a lot. With contacts it is easy and cheap to simulate.

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Hope that helps some,

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Edit: To your original question if you look at the Defocus Curves in that article. You will notice that the EDOF lenses drop off smoothly as the distance gets closer. The MF lenses have bumps where the add powers kick in to boost vision at that distance. And keep in mind that the PanOptix and Synergy may use a bit of both, but still have MF bumps.