Hi. I have still relatively early stage cataracts (first spotted during and eye test 3 years ago). My vision is still good most of the time but I’m having increasing difficulty in low light situations. Night driving has become an issue in the last few months and I’m now avoiding it except for short trips on roads that I know are well lit, I think I’m still safe but I’m not confident. I’m also getting halos and glare, at night, and to some extent in the daytime and have noticed that my contrast sensitivity has declined in all conditions (I’ve not had a contrast test). I’ve recently noticed some occasional ghosted, or double vision of illuminated things like traffic lights, etc but only for green & blue coloured lights. So I’ve decided to press on and get them done now & have found and met with an ophthalmologist who I’m comfortable with and I’m planning to go ahead in a few months time.
So I have to make a lens choice. I don’t want multifocals as I want to reduce my chances of photodystopias so the choice is between monofocal or EDOF lenses.
I use a computer a lot and sit about 3 or 4 feet from the screen. With contact lenses I have no issue seeing the screen but the keyboard is a little blurry (but still usable). I can see a car dashboard with no problem but food on a plate in front of me is blurry. I do need readers for anything printed, unless quite large font) and for my phone and ipad. Without correction I have a bit of accommodation left but have to hold a phone/ipad or printed page about 8 inches from my eyes to focus. My near sight prescription is -4 in both eyes (could be -4,25 now as that was a year ago and I think it’s declined a little), very little astigmatism (-0,25) and no other eye problems.
I understand that the best type of lens in terms of clarity and relative certainty of visual outcome is monofocal (the ophthalmologist is happy to offer mono or EDOF)
My query is, after surgery, with a monofocal lens set to distance would my near vision be as functional as it is now? I know that I would need readers for anything close, but how close? Is it likely that I’d see a dashboard or a keyboard as well as I can now? Would the PC screen 3 or 4 feet away still be clear? I realise that I wouldn’t be able to read up close without correction. Currently I use +1.25 readers when I’m wearing contact lenses and actually prefer the near vision I get with those over my uncorrected near vision (seems brighter and larger)
And would an EDOF lens be likely to offer an improvement on my current corrected vision, and if so, at what cost to my distance?
I generally value my distance vision over my near vision and would be happy to use readers some of the time but obviously would prefer to be as free of them as possible
I realise that everyone is different and there are no guarantees of outcome but would appreciate others real world experiences with both.
The near vision obtained with monofocals tends to vary from person to person. When asked I always say to expect to see well down to 2-3 feet when the distance target is -0.25 D. It is unwise to target 0.0 D as you may end up on the plus side or hyperopic which will hurt both distance and near vision. Personally I can see well down to 2 feet and even down to 18" computer screen letters are still readable but not sharp. I have my other eye set to -1.60 D and my vision of the car dash instruments is the same quality with either eye.
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My suggestion while you can still see well is to experiment with contacts to simulate mini-monovison. Under correct your non dominant eye to leave you at -1.50 D, and see how you like it without any eyeglass correction. You can also evaluate what some +1.25 readers do on top of that. That is essentially what I have, but I only use the readers for very difficult small text in dimmer light. I could use them with my computer which I keep much closer at 15" or so, but do not.
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The best way to evaluate the EDOF option is to look at this document on the Vivity option. I believe the Vivity and Symfony are the only true EDOF, and of those I believe the Symfony actually uses some MF as well. The document illustrates what the Vivity does to contrast sensitivity and also to visual acuity at the various distances. See figures 4 & 5 respectively. You will need to convert the Diopter values to distance by dividing 1 meter by the diopter value. 0.0 D is infinity for distance. And you will also have to convert logMAR visual acuity to Snellen (0 is 20/20, and 0.20 is 20/32). Yes there is a significant price in loss of contrast sensitivity at distance, and a more minor loss in distance visual acuity.
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Vivity P930014 Package insert PDF.
Many thanks. I think we discussed mini-monovision on here last year. I have tried it with contacts in the past a couple of times but didn’t really get on with it.
I’ll have a look at the Vivity link, although we’ve ruled out that lens already because of the contrast issue (big thing for me as I ski a lot and you need contrast in the snow)
Yes, that is it. It wasn’t a link, just a title to search for with google. I have pretty much given up what links are allowed here and which ones are not. The arbitrary moderation of links is one of the most frustrating things about this site.
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On the contrast sensitivity loss with the Vivity I think it is most noticeable in low light conditions, not sunny snow conditions. And if you consider Vivity, I would only use it in your non dominant eye, while using a pure monofocal like the Clareon in the dominant eye set for distance. That way the monofocal can make up for lost contrast sensitivity.
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The other thing to consider is micro-monovision which is targeting the near eye with less myopia in the -0.5 to -0.75 range. This is going to help some with the intermediate distances, but not give you good reading vision with a monofocal, although a Vivity at -0.75 D might be starting to get close.
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If you go with straight monofocals set for distance there are some slight differences. Tecnis 1 provides the least depth of focus, while the B+L enVista provides the most. The Clareon or AcrySof IQ is about in the middle.
Thanks again. I won’t be having Vivity because I want to ski in flat light as well as sunny conditions (skiing vison is particular as contrast on snow in flat light is difficult anyway, without being compromised by an iol or cataracts).
I’ve pretty much decided to have either (undetermined) monofocals or Lentis Mplus EDOFs which my prospective surgeon rates highly and which don’t affect contrast (I understand)
As I say, I’m not that bothered about using readers but being relatively free of them would be a nice bonus.
If you really sit that far from the computer (3-4 feet) you should do fine with monofocals set for distance. You will almost certain,y need readers closer up though. I don’t know anything about the Lentis IOL but I think JnJ Eyhance or Alcon Clareon Monofocal would be good choices.
The Lentis EDOF iol is designed for far and intermediate vision. Their MF iol includes near, far, and intermediate without the rings of Panoptic. The MF category sounds more attractive to me than the EDOF.
Edit:
"Oculentis issued two lens recall notices relating to the Lentis Foldable Intraocular Lenses in 2014 and 2017 to alert providers and users of the surface calcification of the lenses which could lead to opacification.
They subsequently stopped using the cleaning detergent which they identified may have been the cause of the opacification problems.
Oculentis were declared bankrupt in September 2021 after grappling with legal issues over its defective intraocular lenses over several years."
You may want to look at the MTF and Defocus curves for the Lentis lens. Some manufacturers like Alcon with their Vivity publish the curves, and some do not. If they do not, then you don’t really know what impact the EDOF technology has on contrast sensitivity and peak visual acuity. The “there is no free lunch theory” would suggest when you stretch the focal point of the lens there is loss of visual acuity and loss of contrast sensitivity. I am not familiar with the Lentis lens and the technology it uses.
Thanks for that, I was aware of the recalls and the subsequent bankruptcy. These lenses are now made by a different company, Teleon.
I did ask the surgeon than I saw about this and he explained the cleaning detergent issue. He still rates them as the best lens he has used and continues to offer them. He also said that he hasn’t seen a problem with any of them for years now.
The new company also make a similar lens using the same optics but from a different (hydrophobic) material. I understand that this reduces the chances of calcification. I mentioned this to the surgeon and he said that he still thinks that the hydrophilic version is the better lens (he didn’t elaborate as to why but I will ask when I see him again)
MTF basically means contrast. If you spread the available light out over a longer range, the amount of light (and therefore contrast) at any one point along that range of focus will be less than the amount of light at the one point of focus of a monofocal.
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The reason EDOF and MF lenses can get away with this is because in bright light (like daylight) your eye is already getting more light than it needs anyway for a crisp, clear, high contrast image. The trade off is that you will notice the difference in lower light or flat light (think fog, rain, overcast and snowy, etc.)
That defocus curve indicates that lens is a multifocal, not an EDOF. The clue is the bump up in visual acuity as the distance reduces. That suggests it is a bifocal version of a multifocal lens.
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In the Vivity package insert document you can see an MTF curve which is a measure of contrast sensitivity. They include the curve for a standard monofocal to compare to the Vivity. Assuming they are using the same units this would be a good reference.
Thanks again. The surgeon I saw did call these EDOF and stated that he does not use multifocal lenses at all (although that was in response to my asking about the concentric circle type MFs)
Looked a bit more but still can’t find MTF stats for these lenses.
I did however find an article from 2010 which says
“Contrast perception with the Lentis Mplus is equivalent to that of a 20-year-old with healthy eyes” … which sounds pretty encouraging (usual caveats of course) I won’t post the link because of the auto-moderation but anyone so minded could google “Lentis Mplus: An innovative multifocal lens technology”
I think for me it’s going to come down to trusting the surgeon and his advice. I have met with this one once and left feeling confident. He doesn’t have very many online reviews (50 or so) but what there are all good but I’ll take my time before deciding, both about the surgeon and the lenses.
Thank you again for your input on the lenses. Very helpful.
On my read of the Lentis sales information, the Mplus lenses are hybrid EDOF plus multifocal technology. They are quite unusual in that they are like a bifocal with the bottom section providing an Add to get the nearer vision. The Add is what is responsible for the bump up in nearer visual acuity. They seem to come in three flavours with progressing Add power. It seems to me that they would provide vision similar to having a major irregular astigmatism effect. If purity of vision is a desire, they would not be my choice. Here is an article to read that is somewhat dated, but provides a review of choices. The Vivity is not included in the EDOF category, as I suspect it was not available at the time of the article. Also keep in mind that multifocal technology also impacts contrast sensitivity as it effectively splits the light coming to the eye. If it meets a minimum standard the manufacturer may not disclose that though. The Vivity just missed that minimum standard which is why they have published data disclosing it. Other styles may just make it over the minimum and be effectively the same.
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I will post an image in a separate post because it will get moderated that compares some of the monofocal lenses that provide some extra depth of field but fall short of the minimum 0.5 D addition to be called an EDOF.
Here is a graph of visual acuity vs depth of field (focus) with various monofocal lenses on it. It is published by Bausch & Lomb to promote their enVista monofocal as having an increased depth of focus. They and others do this with residual spherical aberration. The Tecnis 1 lens fully corrects the +0.27 um of SA in the average cornea by building in -0.27 um of negative SA. It has the highest visual acuity but least depth of focus. The Acrysof (Clareon will be the same) partially corrects SA and provides more depth of focus. The enVista lens provides zero SA correction (SA neutral) and provides the most depth of focus. It is also said to be tolerant of lens position be off center or tilted. The Eyhance lens does not admit to what SA correction they have used, but based on their claim for extra depth of focus I have added them to the curve. It provides less than the enVista but more than the AcrySof IQ or Clareon. The only issue with the Eyhance is that I believe they change the power of the lens quite quickly in the center area, so it becomes pupil dependent. There may be pros and cons to that. It may not be quite as insensitive to the lens position as the enVista. If your interest is in staying away from the side effects of EDOF and MF one of these lenses that provides some extra depth of focus may be a better choice than diving into a lens that is a hybrid EDOF and MF.
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I forgot to add this image to the post. It shows the defocus curve of the Eyhance compared to the Tecnis 1. It is hard to find an accurate defocus curve for this lens, but this one makes some sense. The is a small loss in peak visual acuity, and extension of the depth of focus. It is worth keeping in mind that they are comparing the Eyhance to the Tecnis 1 lens which has the least depth of focus of common monofocals. If they had compared it to the AcrySof IQ/Clareon it would not look so impressive. And if they had compared it to the enVista it would look worse instead of better…
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Yes, I agree-- on overcast days or when it’s actively snowing, or if you are night skiing you are going to want that contrast! Not to mention on sunny days there are shadows on the snow from trees, and you’ll want to see the snow clearly in the shadows.
Since you want the best possible vision and don’t mind readers, you should get monofocals.
My friend is an airplane pilot and his doctor talked him into getting Vivity. Technically he can drive without glasses, but he still wears bifocals because he wants the clearest possible vision, near and far. On top of that he finds the EDOF annoying when driving because both the street in front of him and every bit of dirt on his windshield are simultaneously in focus!