The Pros and Cons of Mini Monovision

I think the issue is that for some to make a decision on what type of lens to use, they not only have to be convinced the lens they are selecting is the "best", but also need to be convinced that other alternatives are "bad". I feel that can be the driver of negative comments about mini-monovision especially by those that don't fully understand it, or have never tried it with contacts. I think the biggest misunderstanding is that they assume monofocals only provide good vision at a single distance. The fact is that they have quite a wide range of good vision. The distance eye typically sees well from 2-3 feet to the moon. The close eye sees very well from 8" to 8-10 feet. So, not only is the whole range of vision covered, but there is a significant overlap where both eyes see well. As an example my vision of the car dash instruments is equally good with both eyes.

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That aside, there are lots of studies which can be found on the successful use of monovision. The technique dates back to the 1980's with contact use, so there is long experience with it. Here is one example of a study which found mini-monovision with monofocal lenses (AcrySof IQ, or AcrySof IQ Toric) (-1.25 D to -1.50 D near eye, plano distance) resulted in little to no use of spectacles post surgery:

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93% - Computer use

93% - Distance vision

87% - Throughout the day

76% - Night driving

73% - Reading

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Overall "Mini-Monovision Surgery Met Patient Expectations for Decreased Dependence on Glasses" scored 10/10 for satisfaction.

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PMC6230294 Pseudophakic mini-monovision: high patient satisfaction, reduced spectacle dependence, and low cost Debora Goetz Goldberg,1 Michael H. Goldberg,2 Riddhi Shah,1 Jane N. Meagher,2 and Haresh Ailani2

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My personal experience is that I have little to no use of eyeglasses for all situations but night driving in the country with no street lighting. Driving in the city with street lighting is no problem without glasses. With the risk of animals crossing the road unexpectedly I find it hard to justify going without glasses in the country at night. Contrary to the study findings my reading is fine in nearly all situations including reading the menu in dimly lit restaurants. Only very small print (6 point) in dim light gives me issues. I suspect the reading aspect will be quite dependent on what the actual outcome is for myopia in the near eye. If you end up at -1.0 D you are not going to read as well as with -1.50 D. I am at about -1.60 D considering astigmatism. In retrospect I now wish I would have gotten the AcrySof IQ Toric in my near eye, as I think my reading would have been even better. In my next life I will know better!

"I think the issue is that for some to make a decision on what type of lens to use, they not only have to be convinced the lens they are selecting is the "best", but also need to be convinced that other alternatives are "bad". I feel that can be the driver of negative comments about mini-monovision especially by those that don't fully understand it, or have never tried it with contacts."

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First, full disclosure myself: I had what I suspect was full monovision contacts for more than 40 years, and they were great in all situations. Some years ago my eye doctor warned me the latest changes in my eyes were putting me at the outside limits of what worked for monovision, and he was right. The prescription after that left me unhappy about both far and near vision.

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Anyway, I feel what I'm seeing in some posts is beyond what you set out in your quote, some people here have a real negative bias. They aren't just saying they wouldn't choose it because -- reasons, but that it's dangerous, causing falls, overtaxing one eye (my father was blind in one eye from birth; that one eye did fine until his death in his late 70s). My own GP doctor says he has patients who had monovision cataract surgery and are very unhappy. My guess is these are people who didn't try it first with contacts or have it done previously with Lasik. I have a neighbor who tried it with contacts and said it was terrible for her. If she never tried it and had it done for cataracts, obviously she'd have been beyond unhappy. Whether glasses will correct it or not, it's failed expectations. At that point the only plus is at least the poor person didn't pay for a premium lens for their bad outcome.

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It's just always nice to know where people are coming from on these things. I know where you're coming from. I tend to favor the idea because it worked for me, but I accept it doesn't work for everyone and anyone who hasn't had it before ought to think twice. I rather thought doctors refused to do it for anyone who hadn't had it successfully with contacts or Lasik-correction, but evidently not all cataract surgeons are that selective.

i didnt do well with progressives. absolutely hated them. but i am good with trifocal, it isnt exactly the same. the drawback of trifocal for me is traffic lights and car headlights look weird.

ideally i would go with monofocal. if the reading are -0.15 and -0.5 i would consider myself lucky and go with -0.5 iol.

then after a month i would test the iol eye with -1 and -1.5 contact lenses. if that gave me good near i would get another monofocal with monovision and be done with great range and contrast.

if not i would go with trifocal and be done with great range and contrast.

i like these posts as they take into account the psychological and emotional aspects of this issue as well as the obviously important technical issues.

i am fairly sure i will do monovision as i have been experimenting with contacts and am aware this is a degraded version of what the final result should likely be.

we all know everything is a compromise. perfect stereo vision at one distance means reaching for the glasses constantly. monovision means more depth of focus with a drop in overall clarity.

my thoughts now involve whether i would want distance intermediate or near intermediate. i have worn glasses most of my life and so doing the second option would seem more normal. i read constantly, mostly dont drive at night, etc but my desire (vanity lol) would love to be glasses free while in nature/outside/in public is also a factor

anyway, its important people factor all this in. there no other surgery that is remotely as important for thinking about choices from a technical and emotional perspective (unless u r going to let the doctor make the choices for u, like my folks did. anyone on this site is pretty motivated to get good results) besides plastic surgery

I think if mini-monovision is done well one can have both distance vision and near vision. If one comes close to plano with the distance eye, 20/20, or 20/20+ is possible. And if one hits -1.50 D with the near eye vision should be good (20/40) down around a 1 foot or so. If one hits the nominal target of -0.25 D with the distance eye then -1.75 D can be targeted for the near eye while respecting the maximum differential between eyes of 1.5 D. And, if you hit -1.75 D then near vision is good down to even a little less than a foot.

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I think where some get misled on the near vision is that they look at the peak vision point of the near vision eye set to -1.50 D. The peak is more like 2 feet, but useable vision extends down to 1 foot or so. They forget about the useable part. Vision does not drop off a cliff as you get closer and closer. It goes down gradually.

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That said if one is quite near sighted in the range of -5.0 D or so, and you take your glasses off, you get super-vision at close distances. One can see down to inches and your can do jewelry repairs without a magnifying glass. There is no way of achieving that with mini-monovision. You can put on some high power readers though and get that kind of vision.

"i read constantly, mostly dont drive at night, etc but my desire (vanity lol) would love to be glasses free while in nature/outside/in public is also a factor"

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My theory is most of the time when I'm outside in daylight I'm wearing sunglasses anyway, so it's not as if having great distance vision would result in being glasses free outdoors that often. Of course that depends on where you live. I'm in Colorado. Right now I wear computer glasses, which are intermediate and near around the house, and they actually improve distance some -- it's good enough to walk the dog around my familiar property both day and night. I know what I get with say -1.0 in an iol will be up to my particular eye, surgeon skill, and luck, but I'm hoping to function just fine without glasses in most indoor settings, such as restaurants, coffee with friends at their house, the dog shows I still compete at, etc.

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It really is a devil of a decision to make, something you can't test out beforehand but will be stuck with for the rest of your life. This forum, full of how it went for others is so helpful but also can be scary. Ergh!

My sentiments exactly 😃

If one comes close to plano with the distance eye, 20/20, or 20/20+ is possible. And if one hits -1.50 D with the near eye vision should be good (20/40) down around a 1 foot or so. If one hits the nominal target of -0.25 D with the distance eye then -1.75 D can be targeted for the near eye while respecting the maximum differential between eyes of 1.5 D. And, if you hit -1.75 D then near vision is good down to even a little less than a foot.

The quality of near vision in above ideal scenarios is somewhat more individual than you describe. I'm right there (with post-surgical final IOL refractions of -.125D and -1.675D Spherical Equivalents due to very small 0.25D residual astigmatism) and while my distance vision is excellent in all lighting conditions (I feel very safe driving at night with no glasses due to 20/20+ or 20/15 distance vision with no light artifacts, thanks to keeping my mini-monovison from being too large a myopic shift in my near eye), and my intermediate vision is good (great in bright light and good in dim light), my near (reading) vision is sharp at 18"+, or 16"+ is passable in bright light. Definitely not down to a foot for reasonable sized normal print, so I prefer reading glasses for prolonged reading or in less than bright light, but don't need reading glasses for casual reading.

A major factor is pupil dilation (main reason brightness of light affects DoF), which varies somewhat from individual to individual. Eye geometry may also be a factor causing individual variation of DoF.

I'm still very happy with mini-monovision, as I significantly reduced my dependence on glasses while avoiding light artifacts, but individual results will vary, even with the exact same final manifest refractions.

Yes, I have read one study that found patients that were more myopic prior to surgery and had smaller pupils (older person typically), got better than average near vision after surgery. But, as you note, it is very light dependent as that is what determines your actual pupil size. My near vision goes down rapidly in poor light.

"my near (reading) vision is sharp at 18"+, or 16"+ is passable in bright light. Definitely not down to a foot for reasonable sized normal print, so I prefer reading glasses for prolonged reading or in less than bright light..."

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I believe you got the light adjustable lens, so presumably this was a choice you made. May I ask why you chose not to go more nearsighted? For example, did you find that the improvement in reading comfort would not be worth the resulting loss of some intermediate vision?

Correct on LAL and my choice. Reason was I was already at 1.5D difference between my eyes, and I was concerned any more difference would cause problems, such as loss of depth perception, excess point source light artifacts interfering with glasses free night driving, or a disconcerting loss of intermediate vision (none of which I am experiencing). I extremely rarely noticed a small difference in my distance field of view at 1.5D difference and 1.5D is generally considered the max for mini-monovision (more being in the realm of now rarely used full monovision), so I had reasons to believe I was at the upper difference limits. If I had guessed closer on my near target for surgical targeting (my surgeon and I both had reasons to believe 0.75D difference would be close for a final post adjustment target), I might have been able to test overshooting and backing off the difference, but it took 4 adjustments to get to 1.5D with eliminating almost all of my astigmatism, so I locked in with that. It would have required a different post surgical targeting plan to test overshoot beyond that with the ability to back it off if too much.

Thanks for the explanation, JDvision. I am scheduled to get my first LAL soon, in my near-vision eye. So, I'm thinking about how best to target initial lens power and then the adjustments. I guess the lesson here is that while it's great to be able to adjust, the available adjustments are not unlimited, and must be used judiciously. Particularly if you have significant astigmatism to correct - I'm not sure yet how much correctable astigmatism I will have.

That's right, Phil. Adjustments aren't unlimited, so you should have as good an idea as you can on what your primary and backup vision goal is that you want to test out. The less confident you are in final target power, the closer you want your surgical target to be to the range you want to test. Best that the total spherical adjustment range of planned adjustments (sum total in both directions, so from -0.5D to -2D and back to -1.5D, for instance would be 2D total adjustment) not exceed 2D as that is the LAL FDA claimed spherical adjustment limit in either direction.

You can estimate astigmatism adjustment needed by asking how much corneal astigmatism you have (should be measured in your surgical pre-operative biometry). Lenticular astimatism could be making your pre-surgical astigmatism higher or lower, but you'll only have residual corneal astigmatism after your natural lens is removed.

There are no real official designations of what full and mini-monovision is, but when you target -2.5 to 3.0 D in the near eye that is probably full monovision. When you target -1.5 D range that is mini-monovision, and 1.0 D or less would be micro monovision.

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My target was -1.5 D which would be considered mini-monovision. To be clear I did not target to read at 8", that is just what I got, and really only on a bright computer monitor that is about the limit of where I can still read, and closer is blurry. One would have to target much higher myopia to get super clear vision at 8". It is not a reasonable target. And, the reason full monovision is seldom used any longer is that it can leave a gap in vision at the intermediate distances, and it can be difficult to get used to, because of the large difference between eyes. With your expectations, I would suggest -1.5 to -1.75 D would be a reasonable target.

You definitely should try first. The reason not to go by the experience of people in general is that actual results are all over the lot and none of knows where we'll end up. Since the downsides of excessive monovision can include things like headaches and significant loss of stereo vision, which would require another procedure to fix, I think it prudent to target a degree of monovision that your trial shows you live with comfortably (and then leave a margin for refractive surprise).

thank you @RonAKA, my dr called today and agreed to do the distance eye first without a test, as I am far and said I really think the mono, mini or micro would be my best chances of getting the 13" near vision. I am near sighted/myopic in my non dom eye, so maybe he felt okay. But, I am told they might use a Softec HD monofocal lens. I put that term into the search bar in this forum, bit nothing came up. Sounds like a good lens for the Dominant distance eye. Any knowledge of that lens? when I do my other eye, I can figure out if I will get the same for the close vision. Not sure what choices I wil have.

You don't have to use the lens your surgeon wants you to have. If you've done your research, and if the surgeon you are using is familiar with the lens, then choose the lens you think will best suit your needs. If it's a lens your surgeon is not familiar with, but you feel strongly about using it, then find a surgeon who uses it. I ended up changing surgeons because the initial surgeon I was sent to didn't offer the lens I had decided upon after months of research. Alternatively, ask your doctor to tell you in depth why they want to use that particular lens -- the cons, not just the pros of it -- outcomes of the people they've used it on.

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You will do best to do your research on any lens first though, as the blurbs they hand out to you are never going to tell the whole story. I found the comments in the cataract videos helpful, as with the discussion boards. I found the actual outcomes of people who had surgery with a particular lens was far more useful to me than the specs or generic statistics printed somewhere. I don't know what your timeline is, but for myself, I wouldn't be comfortable accepting a lens I can't find anything about. if you can't find information here about the lens suggested, then do a general search for it. Many lenses are used first in Europe years before they are approved in NA, so a broad search might get the info you're looking for. I started out pretty sure that I knew what lens I wanted, then after much reading, watching and asking many questions, ended up researching four other lenses before making my final decision.