What near-vision focal distance should I expect with monovision/toric IOLs?
Posted , 6 users are following.
I had monovision Lasik 15 years ago and experienced complete freedom from glasses.
I recently had cataract surgery with the goal of matching that. The surgeon used AcroSof Toric IOls. My "distance" eye corrected perfectly to 20/20 acuity, but the "reading" eye doesn't focus until full arm's length, so (for instance) it's difficult to read my Apple Watch now. When I expressed disappointment with this at post-op, the doc said that this, in fact, is the target so that I can read the car's dashboard, etc. It seems to me that a comfortable reading distance is a much more frequent and vital daily activity. If I need to wear glasses only in the car, that's OK with me.
First of all, is this focal distance correct for monovision? Should I just accept that I will need reading glasses all the time from now on? As I said, I didn't need correction for everyday reading (books, phone, computer, etc.) prior to surgery.
Second, if this is not correct--if the surgeon missed the target (I realize that it's a bit of a guessing game)--what alternatives do I have going forward? As I understand the physics, I want just a touch more myopia in the near-vision eye. Can a replacement IOL address this? Is there a laser "touch-up" that can provide a solution?
Finally, I should note that I'm less than a week post-surgery. Might the reading focal point move toward me over time--be patient!--as the brain adapts to the implant, or is the initial correction relatively fixed?
Thanks in advance!
0 likes, 12 replies
RonAKA daniel18749
Edited
First, you need to wait 6 weeks post surgery and then get your eyes checked, typically by an optometrist using refraction to get an eyeglass prescription. That will tell you where you stand for correction. It sounds like your distance eye is fine, but the test will confirm what correction if any is needed. Hopefully it is not enough to merit correction. An eye test at 3 weeks will likely be pretty accurate, but it might change slightly by 6 weeks. If you are considering a lens exchange it might be worth it to do it earlier rather than later.
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Then once you have an accurate refraction result for your close then you will know how myopic you are. I have monovision and after much research I believe -1.5 D myopia in the close eye is ideal. It sounds like you ended up closer to plano or 0.0 D. That is somewhat similar to the position I ended up in. My refraction for the close eye is -1.0 to -1.25 D sphere. I've gotten two measurements by refraction at 1.0 D and 1.25 D sphere, and 1 measurement by autorefractor at -1.25. However, this is short of the -1.50 D that I would like to have. And I have some residual astigmatism that I would like to get rid of.
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My surgeon recommended Lasik to make the correction. I have been to one clinic and am waiting for a consult at a second clinic. The first clinic essentially turned me down. They said they could easily get rid of the astigmatism. But, they claimed they could not INCREASE the myopia by a predictable amount. Decreasing myopia is apparently easy. It seems it is easier to flatten the cornea than to make it steeper. Not sure if the second clinic is leading me on, but I clearly stated what I wanted to do (increase myopia by 0.25 to 0.5 D, and get rid of the astigmatism), and the doctor apparently reviewed it and is willing to at least do a consult. Appointment is in August.
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So I think the bottom line is that there are three options. A lens exchange to a different power, a piggyback lens insertion, and possibly Lasik. I am adverse to the lens exchange as my reading vision is pretty good. I don't even really need eyeglasses and don't have any of the correct prescription. I occasionally use +1.25 readers. If I could tweak the myopia just a bit I would be happier, but I am pretty good where I am now. It may come down to whether or not I want to drop about $3K for a possibly risky Lasik, or just live with what I have. I can read quite well down to about 10" or so. With a Jaeger test I see the J3 line quite easily in normal indoor light. In outdoor sunlight I can read J1.
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In your situation if you are off by a lot, and it sounds like you are, then I might consider a lens exchange to get the power right this time.
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Oh and FWIW I have a Clareon monofocal in my distance eye with 0.0 D sphere, and 20/20 vision. I can easily see the car dash instruments, and read a computer monitor at 18" or more distance. I don't believe the close eye has to provide the dash instrument distance vision. The way I am now, I can see the dash clearly with either eye.
daniel18749 RonAKA
Posted
This is very helpful and provides a roadmap of avenues to pursue. I'd be thrilled to have near vision of 10" -- mine is currently about 18", at which point small type (product labels, etc.) is unreadable, regardless of how sharp it is. I particularly appreciate your perspective on the dashboard, which struck me as a poor use-case in any event.
I've set up an optometrist appointment in three weeks as you suggest and will re-evaluate then.
RonAKA daniel18749
Posted
Can you read the dashboard with your distance eye? I would think most people would with a basic monofocal or toric.
foreign789 daniel18749
Posted
I will try to avoid this problem by setting one eye for near vision (reading) and then attempting to gain as much of intermediate/distance vision from the other eye as possible in some (mini-)monovision setup. My first surgery is scheduled for Monday 6/6.
RonAKA foreign789
Posted
The standard mini-monovision approach would be to target the dominant eye for -0.25 D, and then the non dominant eye for -1.5 D about 6 weeks later when you see what you got from the first eye.
foreign789 RonAKA
Posted
I know but reading vision is more important to me than driving or tv.
My surgeon ( a famous one) refused to tell me the exact targets but the plan is to target the non-dominant eye for reading and the dominant eye for intermediate i.e. some degree of mini-monovision. He called it indoor vision.
He told me that I am not a good candidate for full monovision because I have never tried it and some people cannot get used to it. I can not try it now because of my cataracts.
Bookwoman foreign789
Posted
It's good that you have a surgeon who recognizes that not all of us care about distance vision. I have two near-vision (-2) IOLs, and one settled at -2.5. Perhaps he wouldn't tell you the targets as there are no guarantees that they'll be what you actually wind up with.
That said, with this combination I can do pretty much everything except drive and watch TV without glasses. Reading and computer vision are very crisp, and I can see the dashboard in my car very well also (although I always wear glasses when I drive). I do far more reading and computer work than I do outdoor activities, so it's worked out very well for me.
Good luck with your surgery tomorrow!
RonAKA foreign789
Posted
I have to admit that I would be a bit skeptical of a surgeon who will not say what the expected refraction outcome would be in each eye. It sounds like you are going to need eyeglasses to see clearly for TV and driving. Most people doing mini-monovision are attempting to be eyeglasses free.
foreign789 Bookwoman
Posted
Thanks Bookwoman!
I will be happy if I get the result you described .
foreign789 RonAKA
Posted
I expect to wear glasses for TV and driving which is maybe 10% of my time and I am OK with that.
The logic behind my choice is that I work nights and the quality of vision is more important to me than being 100% glasses-free so I decided against Panoptix, Vivity etc. The doctor ruled out full monovision so I think this is the best option for me.
It does bug me somewhat that he didn't want to tell me the refraction targets. I decided that at some point I have to believe that the surgeon knows what he is doing and this one is supposedly good.
RonAKA foreign789
Posted
It does depend on personal preferences and habits. I spend part of the day on the computer about 12-14" away and at the same time the TV on and 15 feet away. I like being able to look back and forth between the two without having to put glasses on or take them off.
john20510 daniel18749
Posted
My surgeon said l have a choice between vivity in both eyes or monofocal distance in one eye and monofocal intermendiate in the other. l dont like the idea of the intermediate eye being a bit blurry in distance and might not get used to it so think l will go with vivity,