Looking for advice on cataract lens choice

Thank you for your reply. Thoughtful and thought-provoking.

It's only on this forum that I became aware of the possibility of having a different focal distance for each eye, which my doctor didn't mention to me as a possibility. I do have a phone meeting with on of the doctors in his office next Monday and I'm going to be asking questions about different focal distance.

Is "mini-mono" the term that describes "different focal distance for each eye"?

Anyway, thanks again for your thoughts and though I am going to take some more time thinking about this (I do not have my surgery scheduled yet, lenses not ordered yet) I probably will end up taking your suggestion. I think they key word in my case is comfort. I love going outside but I spend a lot more time inside, on computer, on phone, around the house. Also, something I haven't seen mentioned: what about faces? What about looking into someones eyes, up close? If you have distance lenses, do you have to put on your reading glasses to do that? 😃

It seems better to stick with what you're already comfortable with, as much as possible.

This. David, I'm sure you've read my posts on other threads, so don't want to repeat myself too much. I'll just say that with an outcome of -2 and -2.5, I can easily read, use the computer, and do just about anything indoors without glasses, except for watching TV (and I can even do that if it's something like the news, where I don't have to see fine details.) Lens choice should be based on the life you actually lead.

Monovision is the general term for eyes having different focal distances; mini-monovision refers to the extent of the difference, measured in diopters, between the two eyes. Typically, a difference of 1.5 D or less is considered mini-monovision (and usually but not always can be accommodated without difficulty). Sometimes the term micro-monovision is used to denote an even smaller maximum difference, again measured in diopters, between the eyes.

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Like you, I was nearsighted my entire life, wearing glasses from third grade. At the time of my cataract surgeries earlier this year, my prescription was RE: -6.00 / -0.50 / 10 ; LE: -7.75 / -1.25 / 160. The Add, for the progressive lenses I used, was +2.50 in both eyes.

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After discussion with my first surgeon and extensive reading, I decided that I did not want to run the risks involved with defractive (multi-focal) lenses and that I should trial monovision using monofocal contact lenses. Trialing monovision is important because it can give you and your surgeon a good idea of the amount of monovision you'll be able to tolerate with IOLs. Because coming within 0.50 D of the surgical target is regarded as a normal, good result, it makes sense to trial a greater degree of monovision than you and your surgeon are thinking of targeting with IOLs. The difference between what you can accommodate with contact lenses and the targeted surgical difference provides a margin for what the surgeons sometimes call refractive surprise.

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Along the way I switched surgeons. Self-reflection and discussion with my second surgeon led me to prioritize near over distance vision. (With mini-monovision, good intermediate vision should be possible with either priority.) My surgeon recommended this approach, and I agreed, because potentially being somewhat myopic and needing glasses for distance vision was a less disagreeable prospect than frequently having to put on and take off readers as I switch between working with my desktop computer and reading printed materials, or needing to put on readers to read material on my smartphone. YMMV.

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Having decided to prioritize near vision, we also decided to begin with my "near" eye. If the result did not provide satisfactory near vision, then I could decide whether to try again or, changing my original approach, go for distance vision in my dominant eye. On the same basis, someone prioritizing distance vision would start with the "distance" eye.

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Importantly, we scheduled my two surgeries six weeks apart. First, this gave me a second trial of mini-monovision, using a contact lens in my unoperated eye that approximated the notional surgical target. Second, because it can take some weeks before the operated eye becomes reasonably stable, putting off the second surgery gives the surgeon more information for choosing the refractive target and IOL power for the second eye.

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Of course, the choice of IOL also can matter. Reading and both my surgeons' recommendations led me to the Eyhance because it offers a modest increase in depth of focus over conventional IOLs like the Tecnis 1 and Alcon Clareon monofocals.

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Luck also helps. Now 2-1/2 months after surgery on my second eye, I have excellent near and intermediate vision and good enough distance vision to be able to drive comfortably in all conditions, watch movies, etc. More concretely, one month post-op my near vision measured J1 and my distance vision measured 20/25. On a spherical equivalent basis, the measured refractive results were RE: -0.50 D / LE: -1.50 D.

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Just to be on the safe side, for potential use when driving in poor visibility conditions or unfamiliar areas I did buy eyeglasses. To preserve my ability to view the dashboard, I got them in a mini-monovision prescription. Ignoring axis, it's RE: plano / -1.00 ; LE: -1.25 D / -0.50. In practice, having also chosen Transitions Xtractive Polarized version (because they activate inside the car) and because the lenses themselves are much, much thinner than my progressives and I put them in the ultralight Lindberg frame I used pre-surgery, they've become my general sunglasses.

When you say "with an outcome of -2 and -2.5", does that mean that the result isn't exactly what is targeted pre-surgery? In other words, did you target -2 and got -2/-2.5, so that there is an element of unpredictability to the outcome?

"Importantly, we scheduled my two surgeries six weeks apart. First, this gave me a second trial of mini-monovision, using a contact lens in my unoperated eye that approximated the notional surgical target. Second, because it can take some weeks before the operated eye becomes reasonably stable, putting off the second surgery gives the surgeon more information for choosing the refractive target and IOL power for the second eye."

I like this idea but I wonder if it's possible to trial mini-monovision with glasses instead of contacts? After the first-eye-surgery, get a clear-glass lens on one side of the spectacles (the side with the just-operated-on eye) and then a trial prescription on the other side, to mimic the mini-monovision result after the second surgery?

Exactly. I have -2 IOLs in both eyes, but my left eye wound up at -2.5. Our eyes aren't machines, and depending on how they heal, the lens can move slightly forward or back from where it's placed.

As with much else here, it depends. First, you'll see different-sized images from each eye. Second, it's likely to cause eye strain and may produce double vision. Third, while over time some people are able to fuse the two images together, you may not have enough time unless the date for surgery on your second eye is far in the future. On the other hand, glasses may be better than nothing if you're unable to wear a contact lens in your unoperated eye.

"I am currently at -0.375 D in my distance eye, and -1.60 D in my near eye"

Thanks for your reply, very interesting. I have 2 questions about the numbers you chose, and which I quoted.

1. are these the choices you made prior to surgery and the surgery matched your choices exactly? Or was this the outcome and you actually chose 2 slightly different numbers? (I'm just wondering how exactly the choice matches the outcome)

2. What would be a "pure distance" number? 0.000 D ?

Thanks again.

When I had my first eye done I was a total rookie at this. The basic target for my first eye was distance or plano. In a perfect world this would be 0.00 D Sphere, and 0.00 D Cylinder (astigmatism). The surgeon I had was not all that forthcoming with detail, and at that time I was not smart enough to ask for it. I recall he said that I did not have enough predicted astigmatism for a toric lens and one method he used was predicting 0.0 Cylinder (astigmatism), while the other was saying -0.40 D. He said is experience was that the outcome generally fell between the two. On sphere he said one power was predicting essentially 0.0 D, but he did not recommend it as there is always some error between what is targeted and what you get, and he did not want to go positive (far sighted). He said nobody ever thanks him for leaving them far sighted. The next step was predicted to be about -0.37 D or so. I agreed. The outcome was 0.0 D Sphere, and -0.50 D Cylinder. On a spherical equivalent basis which is sphere plus 50% of the astigmatism, the outcome was -0.25 D SE. That was about 3 years ago, and on my last exam my Cylinder had increased to -0.75 D, so now a SE of -0.375 D.

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On my second eye I was more well informed, from information I gained here, but I still did not ask for the IOL Calculation Sheet, which I should have done. I used the interval between the first eye and the second to use a contact in the unoperated eye to simulate mini-monovision. From this simulation and other information on the ideal amount of myopia in the near eye, I basically used a contact that left me at -1.25 D and thought that was pretty good. I got a valuable suggestion from a contributor here to try reading glasses with my now operated on eye which at the time was -0.25 D SE. This with the Jaeger chart convinced me that -1.25 D was not enough and -1.50 D was better. In comparison to a natural lens, the IOL has no accommodation ability so it needs a little more power to read with. Interestingly this is essentially the same testing that Dr. Barrett recommends in that article I gave you. I was not aware of the article at the time. It is a good method to finally select the near eye power, and I recommend it.

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Astigmatism was more significant in my second eye and was determined to be irregular. The surgeon was on the fence on whether or not I would benefit from a toric. In the end we decided not to use one, and he suggested I could always use Lasik to make an adjustment after the fact. So he used the predicted astigmatism to reduce the Sphere target to get a SE of -1.50 D. And he pretty much hit it right on. My Sphere has shifted by about 0.25 D since and I am currently at -1.25 D sphere, and -0.75 D cylinder for a SE of 1.625 D, on a calculated basis. With the consideration that refraction is really only accurate to +/- 0.25 D, that is essentially -1.50 D, or right on target.

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What is your current eyeglass correction? If it is substantial there can be some issues with doing the monovision simulation. Contacts more accurately predict monovision as they sit right on your cornea while glasses are away from your eye. And, there are always some issues to consider when going with one eye surgery done, and not the other.

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One other thing to consider is that some confuse anisometropia with monovision. Anisometropia is just a fancy word to describe the differential in refraction between the eyes. Monovision is seeing for distance with one eye and seeing close with the other eye. To do that you need to induce some anisometropia, but as that Dr. Barrett article states it is the refraction target in each eye that is most important. You want to get as close to plano as possible, without going positive, to get good distance vision, and use as little near myopia as possible while still getting acceptable near vision. The reason to avoid high amounts of myopia is to maintain reasonable 3D vision and a good range of binocular vision. Anisometropia should not go over 1.5 D, but it is the individual refraction of each eye that determines what you will see.

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Hope that helps some,

Yes. It does help. Thank you. My prescription is -2.00 left eye and 0.00 right eye. I used to need some correction in my right eye, but in recent years it has changed to zero.

That prescription should be easy to deal with. It actually is quite close to monovison if you go eyeglasses free now. The left eye is at the lower end of full monovision, and in my opinion a bit to much. But, it would give you a flavour of what it is like. If you were to use a -0.50 D contact in your left eye that would more accurately simulate mini-monovision.

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Which eye is your dominant eye? Is the cataract worse in one eye?

My prescription is -2.00 left eye and 0.00 right eye.

I would think that that would be nice, now that you know your brain is compatible with that. So I would suggest a little closer for the close eye than Ron does. I am going thru these thoughts before getting my close eye done.

Eye prescriptions have 3 numbers per eye.. you quote sph numbers. But the cyl numbers are important in this discussion too. Axis is not important to this discussion.

I would particularly consider RxLAL in the distant eye. The conventional lenses cannot be relied upon to get as close to zero. RxLAL still has 0.25D target granularity due to the software. If there is astigmatism, the fact that that is adjusted after installation means that the angle during insertion will not matter.

My left eye is:

1. dominant
2. worse cataract
3. life-time most near-sighted

So normally dominant eye gets distance lens first, but in my case, dominant eye gets near distance lens first.

btw, just talked to an optometrist who measured my glasses during the last visit for cataract preparation and she said my left eye is -2.50, not -2.00

It would make a lot of sense to do the left eye first, and do it for full distance based on the fact it is dominate, and has the worst cataract. It is really not a big consideration that it has been more near sighted for life. If you have been able to correct it with glasses, it should be quite correctable to full 20/20 distance vision with an IOL. About all it means is that if you correct it to distance with an IOL and want to simulate mini-monovision after surgery you would have to use a +1.50 D contact in your right eye to make it myopic. That is easy to do. If you have never worn contacts there are some that are better than others that I can suggest. And if you want to correct the left eye to plano before either eye is operated on, you of course would need a -2.50 D contact or close to it. Sometimes there is a small adjustment from an eyeglass prescription to a contact prescription.

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Also as @trilemma has suggested, don't forget to consider the possible complication of astigmatism which shows up as a cylinder number on an eyeglass prescription. If you have never had any, that is a good sign.