Questions on mini-monovision and dominant eyes

Thanks, Ron. That definitely helps.

One on my biggest challenges is that I’m 56 years old, and even with the astigmatism, I have rarely worn glasses. I should be wearing glasses for distance vision, but I can drive and function perfectly fine without them, so I just haven’t bothered. Uncorrected intermediate and near vision are great, at least in my left eye. So I fall into that category where if I get the two monofocals set for distance, I should get the clear distance vision that I haven’t had since my late teens, but I may have to give up my intermediate and near vision.

I started looking at monovision again, and then came across mini-monovision. All things considered, your result of good vision 12” and out is a compromise I can definitely live with. Poor vision anywhere from 6’ to 2’ in? That’s going to be brutal.

I’m very encouraged that you describe yourself as a perfectionist and that you’re satisfied with your vision. That bodes well for me. Right now I think I’m seeing out of both eyes even though I’m really only seeing out of one. I knew something was definitely off, but I wasn’t even aware that my right eye was bad until I had my exam. I’m hoping that also bodes well for mini-monovision as an option.

Also, thanks for clearing up the dominant eye question. That buys me some more time since I now don’t have to make a decision before my first surgery. I’ll have another talk with my surgeon during the next day follow-up appointment.

Thanks again. I’m feeling a lot better about my options after reading your reply!

The nearer vision outcome that people get from a monofocal set for distance seems to vary. I can start to read a computer screen with my distance set eye at about 18". But, I find it too far for comfortable computer work on my 24" monitor. I have no trouble at all reading my dash instruments in my car, truck, and motorcycle. However, I seem to get closer vision than what others report.

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Keep in mind there are options to see a little closer than a pure aspherical monofocal. The B+L enVista is one example. Instead of targeting zero spherical aberration like the Tecnis 1, or -0.07 like the AcrySof IQ or Clareon, the enVista brings spherical aberration down to neutral which leaves one at +0.27. This does not provide quite as much visual acuity but it increases the depth of focus. Another choice would be the J&J Eyhance which provides a minor amount of extended depth of focus. Vivity is a step further, but it also brings with it increase risk of optical side effects.

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Others have success with these lenses, but my preference is to stick with the pure monofocal and use mini-monovisioin to get the full range of focus. I think the Clareon monofocal is a good choice for mini-monovision. I have one in my second eye, and the older AcrySof IQ in the first eye.

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There are some compromises to mini-monovision. They will only provide good binocular vision in the 18" to 72" range. Two eyes in good focus will improve vision. Outside that overlap range vision will step down a touch in crispness. That said I still have 20/20+ with both eyes open at distance.

Would you please explain hyperopia? Thank you.

feddi it means someone is farsighted

That is correct. I would just add that there is nothing good about being far sighted or hyperopic. Some use the term to describe vision where one can see well in the distance but not close up, which is actually presbyopia. For the best distance vision far sighted people need to be corrected too. They use glasses which require a + correction instead of a negative correction. If the correction is significant, you can tell whether a person is far sighted or near sighted by just looking at the size of their eyes through the lens of their eyeglasses. Glasses for myopia make the eye look smaller, while glasses for hyperopia make the eye look larger.

On hyperopia vs. myopia:

If you have mild nearsightedness, for example myopia that can be corrected with -1D sphere glasses), your uncorrected eyes have the best focus about 1 meter in front of your face and will look less clear as you move further away from that distance. You probably won't notice the lack of clarity until you look at something 4 or more meters away and then it might appear a bit fuzzy.

With more severe myopia (-5D correction), you see clearly at 20cm but probably can't see much beyond 25 or 30cm. When these folks want to read fine print, they can always take off their glasses and read it if they hold it close to their face. If held close enough they can see fine details without magnification that non-myopes cannot. Sometimes this is referred to as the "gift of myopia."

With hyperopia, your eyes focus best beyond an infinite distance because the light coming into the eye is focused beyond the retina. You can't see any distance optimally without magnifying (concave) glasses. There is no "gift of hyperopia."

In contrast, if you end up hyperopic +1D or more with an IOL, you likely won't be able to see well at any distance without glasses. The ideal distances to see with the IOL will all be beyond the visible range. Contrast sensitivity will also be a problem in low light. The closer you look, the fuzzier the vision. Almost certainly no intermediate or near vision. It can be corrected with glasses/contacts but you'd need to wear them all the time. While I've never been hyperopic, I'd guess that it's harder to correct the near distances than the far since it takes a more powerful plus lens. The opposite is true with severe myopes - it's harder to correct for distance than near.

If you end up -1D with a monofocal IOL, you'd have good contrast sensitivity and decent vision within 0.75D or so of the target (50cm to 4m) all in the visible range. Any corrective lenses for near or far would be 2D less powerful and likely be easier to get an ideal correction in either direction.

There are no advantages of a hyperopic IOL outcome. If you want the absolute best distance vision (at infinity) it will be achieved at plano (0D). If lucky, you might get 20/15 or better distance vision with a plano outcome. If you are similarly lucky but end up -0.25D or +0.25D, you'll likely still see 20/20 at distance. But the -0.25D outcome will give you better intermediate vision (beyond 80-100cm) than the +0.25D outcome (decent vision beyond ~130-200cm). The -0.25D outcome will also give you much better low light vision and contrast sensitivity at any distance.

Thank you lynda

I meant to say that for night driving, I feel more comfortable with glasses.

All considered including your limitation to J&J lenses and your objectives, I think the Eyhance is a very good choice for you in the near eye. It does not offer a lot of extension in depth of focus, perhaps about 0.35 D, but it also seems to have minimal side effects of flare and halos. Symfony would provide more but with a significant step up in potential side effects. @Sue.an2 here has Symfony lenses and could comment better.

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What would an Eyhance set to -1.0 D be like for distance vision? It would be somewhat equivalent to a monofocal at -1.35 D. My near eye with a Clareon monofocal measured by my optometrist is at -1.0 D Sphere, and -0.75 D Cylinder. Converted to Spherical Equivalent that is -1.375, or essentially the same as what you should get with an Eyhance targeted to -1.0 D and assuming residual astigmatism is negligible. And, unfortunately toric lenses come in quite large power steps and even with them getting cylinder to zero is quite difficult. My wife has a toric that brought cylinder down from about -1.0 to -0.5 D. She gets 20/20 vision with the eye as sphere is 0.00. From what I can see in the literature the LogMAR of an Eyhance at distance and set to -1.0 D would be about 0.35. That corresponds to a Snellen between 20/40 and 20/50. That is very close to what I have in my close eye, and with my perfectionist standards, not very good for distance. I would not at all be happy if I had that outcome in both eyes. I'm 100% sure I would be wearing progressives full time if I had that outcome in both eyes.

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My thoughts for an eyeglass free solution would be to target an Eyhance between -1.0 and -1.25 D for the near eye, whichever one you decide you want to be the near eye. And in the distance eye you want to target -0.25 D and for the best vision use a monofocal Tecnis 1 rather than an Eyhance. The combination of these two should give you near full range of quality vision.

Hi Thomas,

I'm glad you're getting some good info from the comments. I think you're right in that it's wise to speak in detail with your surgeon about which course to take. I'd like to share my thoughts as to how I would approach your situation if I were you. First I would do as much research as you can on the lens options and strategies we've been discussing. Makes sure that everything "makes sense" to you so that ultimately you have no regrets, that you feel you gave it your best fully informed shot. Second, I would consider my ideal desired outcome whilst leaving options open for outcomes that, whilst not perfectly ideal, are still quite satisfactory. In your specific case (and again if I were you) I would actually try to get your true dominant eye set for distance. To be conservative, you could target the dominant eye for -0.25D to -0. 50D with perhaps a monofocal lens or an Eyhance or something like the Rayner EMV ("EMV" stands for "Enhanced Mono-vision) that I have (but I know you might need to go elsewhere for the Rayner lens). But once you've got the dominant eye nailed down successfully for distance, it's rather low hanging fruit to get success with the non-dominant second eye for near vision in a mini-monovision scenario particularly, in my opinion, with an EDOF lens. You can pretty much target from - 0.50 to -1.00 and wind up quite well off. You may notice I'm going a bit counter to your suggestion of targeting at -1.00D in that first eye. This is because I think it's important to have your best shot of getting at least one eye satisfactorily set for distance, and in my scenario you have two attempts at that. If you target -1.00D and you hit that mark and/or there's a refractive error (however unlikely) putting you at -1.50D then you've mainly just got one more shot at plano with the other non-dominant eye. If I may digress for a moment and tout what I've come to learn are the benefits of the Rayner EMV lens (I do not work for Rayner by the way. I'm just a satisfied customer of that lens), know that the lens was designed specifically for a monovision strategy in mind by one of the top experts in the world (Graham Barrett). Even when both eyes are targeted to plano with that lens, 70% of subjects in a study achieved good functional reading vision in addition to excellent distance and intermediate vision with no dysphotopsias or detectable loss of contrast. I think that's pretty compelling. With an offset of just - 0.50D in a mini-monovision scenario it seems very likely excellent reading would be achieved in virtually all cases. If the Rayner EMV lens had been available when I got my first eye done I would have most certainly chosen it for my distance eye. As it is, I have a monofocal for distance in my non-dominant eye and the Rayner EMV in my dominant eye offset by - 0.75D. But I'm still quite satisfied. Ultimately you need to decide what you and your surgeon are comfortable with for your needs in your specific case. I'm just giving you my opinion and the way I thought about things when I went through the process of lens selection, strategy, etc.

Indy G

Yes, I agree. After giving it more thought, I'm going to proceed as planned with the monofocal Tecnis 1 set for distance and see what that looks like before making a decision on the left eye.

My gut feeling is to just do both eyes for distance with the monofocals and wear the glasses. My track record with going outside the box when it comes to any decision like this isn't stellar. Fortunately, the cataract isn't that bad yet in the left eye, so I want to try a -1.0 to -1.5 contact lens for a week or two and see how well I adjust. The more I think about it, the more I think going into even mini-monovision with no trial run whatsoever might not be wise for me personally despite the success that all of you have had.

Yes, I know. I'm a big chicken! LOL

Yes, if your vision is still good in your left eye, there is no point in rushing into doing it. What is your eyeglass prescription in the left eye? If it is quite strong then there may be some issues to work around for the period of time you have the right eye done, and are waiting to do the left eye.

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It is a good plan to do a contact lens simulation of monovision. Because you are younger your eye probably still has some accommodation ability. That will give you a bit of an optimistic view of how much myopia you need to read well. When I did that exercise I determined -1.25 D was ideal, but with an IOL in place and all accommodation gone, -1.5 D was better.

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You mentioned astigmatism correction. If you eventually plan to get a toric in the left eye, it would be best to simulate that with a toric contact to correct the astigmatism. Astigmatism aside, for example if you are currently at -2.0 D for eyeglass prescription then you would want to try a -0.5 D to simulate -1.5 D.

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The contacts I found the best when I tried many were the CooperVision MyDay (sold by Costco as Kirkland), Alcon 1, and J&J Acuvue Oasys. If you belong to Costco it is a good place to get them as I found they were quite liberal in giving out free samples to try. And, I pretty much tried every one they had samples of... I settled on a non toric Kirkland, and used them in my non operated eye for about a year and a half. I found that to be better than progressives that had the post surgery correction in them.

One could do the contact lens test with drops put in the eye to temporarily paralyze the accommodation response. That is what one of my ophthalmologists suggested. It wouldn't be a long-term test, but it would provide useful info on what your reading refraction should be. For that purpose, it could be lenses in a trial frame rather than a contact lens.

thomas,

I used the Tecnis 1 monofocal set for intermediate vision in both eyes and I see 20/25 and 20/30, without glasses, which is good enough for me. I see my computer very clearly, drive great in the dark, all without eyeglasses. I only need readers for close up reading of small print. I did not correct my astigmatism with a toric or with limbal relaxing incisions. I had planned to correct it with glasses, but I didn't need to. That was how it worked out for me. You may want to consider Intermediate vision, but the refractive outcome after cataract surgery can vary from person to person.

I think the main purpose of a contact lens test is to determine how comfortable one is with the difference in correction between the two eyes. Probably the most accurate simulation of the myopia needed without accommodation is to just buy some low power dollar store readers and try them with your IOL eye which has been corrected for distance. Tests I did while still having some accommodation were favouring -1.25 for myopia. But after I had my first eye done for distance, the test with +1.25 and +1.50 readers pointed me toward the -1.50 target.

Lynda111,

what is your refraction? Your results sound like my vision with glasses set to -0.75 under correction.

My surgeon said that with Eyhance set to -1D and minimal astigmatism, I could expect to see 20/30 at distance. He was being conservative. At distance, I see 20/20- out of each eye, one set to -1.3D and the other -0.9D. At 3-4 meters (TV distance), my vision is indistinguishable from 20/20.

Despite setting the lenses to -1.3D and -0.9D, when refracted using the "plus-max" technique, my prescription is 0.0D in the near eye and +0.25D in the far eye. As mentioned elsewhere on these forums, this is indicative of a long flat landing area for Eyhance that has been reported in some international journals, but interestingly, not in J&J's study. Targeting intermediate takes full advantage of that landing area and gives very good distance vision along with intermediate and decent near.

Eyhance also tends to shift the vision more hyperopic in low light when the pupil is large because the power changes from the periphery of the IOL to the center. I'd be careful about targeting close to plano with Eyhance. That moves the good vision in the landing area outside the visible range and probably leaves you with limited intermediate/near, especially in low light when your pupil is large.

Thank you everyone for the replies. This is like throwing a dart. I think I'd be very happy with pretty much all of your individual outcomes, but it seems like each of you got there in very different ways. About the only common denominator is that SOMETHING is going to need to be targeted for intermediate, whether that's both eyes, the dominant eye, the non-dominant eye, a Tecnis monofocal, an Eyehance, etc.

Unfortunately, it's been so long since I had a pair of eyeglasses that I couldn't tell you what my prescription was before the cataracts. That's part of the problem.

I haven't had great distance vision since I was in my teens, so I'm used to that. I'm pretty sure 20/25 would be an upgrade. 20/30 might be as well, or at the very least, similar. If someone said "We can give you the same result Lynda got", I'd say "Where do I sign?!?". However, I understand it doesn't work that way. I could do exactly what she did and end up with a completely different result due to refractive error, residual astigmatism, size of pupil, color of shirt I'm wearing the day of surgery, etc. 😉

This is maddening. At least I'm still three weeks out from having the first eye done, so I have some time to figure it out.

I just booked another consultation this coming Tuesday afternoon with my surgeon. If I don't settle on a plan of action, I'm going to drive myself and everyone around me insane over the next three weeks.

After I have my consultation, I'm going to drop off for a bit, but I will come back after the second surgery (tentatively scheduled for Dec 22nd), to discuss which direction I went in and how the results turned out. I just don't want to start second guessing myself (or my surgeon) after we agree on how to proceed, so I need to stay off the internet (as far as cataracts and lens are concerned) until the surgeries are done.

Thanks again to each and every one of you. I wouldn't even be having this discussion with my surgeon if it hadn't been for all of the great feedback I've received here. I'm far more informed and prepared to make this decision than I was a week ago.

I think one thing to keep in mind is that defocus curves for these lenses are based on the outcome of a number of patients. I suspect some of the studies do not have all that large of a sample size. But, in any case these curves have, or should have, error bars associated with them that define the probable limits of outcomes. The ones that I have seen have error bars so large that there are people with monofocals that get better outcomes than those that have the Eyhance lens, or even the Vivity. The point is that while you obviously got an exceptional outcome, it would be unrealistic to expect everyone to get the same result. Certainly one could hope for the best, but it would be more reasonable to set expectations based on the average outcome while hoping for the best, and being prepared for the worst.

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As an example I can read text on a computer monitor at about 18" with my AcrySof IQ monofocal with a refraction of 0.00 Sphere, -0.50 Cylinder, and SE of -0.25 D. However, I know that is significantly better than predicted by curves. I would not want to promise anyone that outcome, and 24-36" is more realistic with this monofocal. On my other monofocal eye which is -1.00 Sphere, -0.75 D Cylinder, and SE -1.375, I am between 20/40 and 20/50 for distance vision. This is pretty much right on the average to be expected. I did not get exceptional results in this eye. The astigmatism may be playing a part in this of course.

I would suggest a very minimum of 6 weeks between surgeries. This will allow the first eye to heal, and the refraction results to be accurate. In turn this will be good information on making a decision on the second eye. My surgeon says he always learns something from the first eye that he can apply in the second eye.

Jim

my cataract surgeon gave me a refraction prescription but I never filled it cause I see fine like I am.

But as others have said how well you will see after cataract surgery cannot be predicted. It varies from patient to patient and depends on a variety of factors.

Wow, you guys really impress me with your knowledge of vision. I had cataract surgery 8 yrs ago in my left eye & 7 yrs. ago in my right. My surgeon pretty much told me to do research on the different lenses. I had a multifocal tecnis lens done in my left eye first. He miscalculated his measurements & I had to have PRK to correct that. Then he decided to do YAG laser not long after. I struggled with letting him do my right eye after that. I was not happy with the outcome of the left eye at all. I took a chance and let him do the right eye with a monofocal tecnis set for distance. I was happier with those results but still not 100 % satisfied. Now I'm having blurry vision in both eyes now & he tells me he can do a lens exchange in the left eye. I had choreoretinitis in that eye close to almost 50 yrs. ago which left a hole in my retina & left me with alot of floaters. I also developed more floaters in that eye after the YAG surgery that he did. He told me my vision could not be corrected with glasses. Just went to my husband's doctor who is an optometrist & he prescribed some glasses which does help clear somewhat but makes me feel dizzy & paranoid to drive. He told me to definitely not have the lens exchange because of the high risk of complications which is why he prescribed glasses. I agree because I am post yag & I know the surgery will be riskier. He also told me I am going to need Yag on my right eye but not right now. I think I'm too scared to let my cataract surgeon do anymore surgeries on my eyes even if it is laser YAG. I do not like looking through smeared eyes as best as I can describe it besides the terrible ghosting that I experience in my left eye. Any advice would be greatly appreciated. Thanks.

There are some definite limits to my knowledge of vision issues, and the ones you have definitely push those limits for me. About all I can offer is that there are some issues with doing a lens exchange after you have had the YAG procedure. Essentially YAG is cutting a hole in the bag or capsule that contains the IOL. IOLs have a variety of haptics or legs that center the lens in the bag and keep it stable. As I understand it having a hole in the bag limits the types of replacement IOLs that can be used, while still keeping them centered and stable in the bag. So, all I can say is to be careful with that possible option. Getting second and third opinions would certainly be warranted. All said it may be best to settle for the vision with glasses.

Thank you for your response Ron. It is much appreciated & I'm definitely going to take your advice.

I had my final consultation with my surgeon this afternoon. We were able to establish that my right eye is dominant, and that's the one with the worst cataract that's being operated on first. Their default lens for femto laser assisted surgery is the Eyehance which works for me. Throughout my research, it's received very positive reviews.

I will be getting the toric version of the lens to help correct my astigmatism. We will be targeting -.25. Based on the results, we will decide what we want to do with the second eye. If I'm happy with the result, we will target -.25 for my left eye as well. If I'm not where I want to be, we will target -1,0 to -1.5 for the second eye. I'll post again after the first surgery is done.

If you use an Eyhance in the second eye you may get away with a target of -1.0 to -1.25 D. But, you are wise to decide that after the first eye is done and you can see what plano looks like.