The Pros and Cons of Mini Monovision
Posted , 34 users are following.
In view of the recent posts with misinformation about Mini-Monovision I thought I would post my experience with actually having Mini-Monovision. I first used monovision when I was wearing contacts for distance vision and I got to the age where presbyopia started to become an issue. Taking contacts out to read, and then putting them back in again, is not really a viable option, so with the help of a contact lens fitter I set one eye up for closer vision and the other for full distance. It worked very well for me, but with all of the issues associated with wearing contacts. I did it again for about 18 months after I got my first cataract surgery with a monofocal IOL set for full distance, and used one contact for the near eye. That worked well, so I proceeded to do it with my second eye using an IOL. I ended up at -0.25 D in the distance eye and -1.40 D in my near eye. Astigmatism compromises my vision a bit in the near eye, but all in all I am extremely satisfied with the outcome. I would not hesitate to do it all over again. The only thing I would do differently would be to get a toric in the one eye that turned out needing it. So what are the Pros and Cons of doing it?
.
Cons:
- First you have to accept a slight decrease in distance visual acuity as at full distance you will not have much binocular summing effect. My distance eye alone is 20/20+. If both eyes were done for distance, I expect my binocular vision would be 20/15. So, I did give up half a line of visual acuity.
- From my minimum distance of vision at 8" out to 18" I do not have much binocular 3D vision. I have threaded a needle, but I think if one was sewing for hours, some +1.25 or so reading glasses would make it easier. From 18" out to 7 feet or so, I have very good binocular vision. I would expect that monovision would not make for a good excuse for swishing on a tennis or golf swing.
- For reading very fine print in dimmer light you will likely need reading glasses, or a light. I use some +1.25 D readers perhaps once a week or so. I don't bother bringing glasses with me when I go out shopping or pretty much anywhere. I have had no trouble reading menus in dimly lit restaurants. I may put readers on momentarily once a week or so, for a particular task. But, they come off immediately as I dislike looking at anything of any distance with them on.
- I drive at night in the city, but for safety purposes I do wear a pair of prescription progressives when I drive out of the city on dark roads at night. I worry about a deer or moose coming out of the ditch and not having time to see it. I may wear my prescription glasses once a month or so.
- You may have trouble finding an Ophthalmologist that will work with you to get properly fitted with the correct IOL powers to achieve good monovision. Some just do routine distance vision in both eyes without even asking what you want. Some seem unaware of how it works. And I don't like to play the conspiracy theory card, but I suspect some find the "premium" lenses much more profitable than doing monovision. Monovision just needs standard monofocals which are the lowest cost and I'm sure the least profitable for them.
- If you have difficult eyes with prior laser surgery, or are at the extremes for myopia or hyperopia, it can be more difficult to hit specific refraction targets needed for monovision. In this case your will want to have a surgeon that will be very careful selecting IOL Power formulas, and making sure the power is as correct as possible. You may also want to consider surgeons that use the Alcon ORA system to measure the power during surgery to ensure higher accuracy.
.
Pros:
- Aspherical monofocal lenses bring all the light to a single point and for that selected point give the highest visual acuity. With a monofocal each eye is set to a different distance. Normally the dominant is set for distance (0.00 to -0.25 D), and the near eye set for -1.5 D, or about 2 feet. This gives the brain two options for vision, and with each eye there is quite a wide range of distance they are still effective at while being off peak. The brain does a good job of blending the images together as one.
- Compared to multifocal (MF) lenses and extended depth of focus (EDOF) lenses an aspheric monofocal has a high contrast sensitivity at the peak focus point. So this gives maximum contrast sensitivity in the distance eye at night for driving, while the other eye can provide maximum contrast sensitivity up close, like when reading a menu in a dimly lit restaurant.
- Monofocal lenses, unlike MF and EDOF lenses have very minimal optical side effects like halos, flare, and spiderwebs around point sources of light at night.
- Monofocal lenses have the lowest price and in many jurisdictions it is at no cost. This compares to MF and EDOF lenses which have a premium price in the range of $5,000 to $6,000 a pair.
- If the focus point differential between the eyes (anisometropia) is maintained in the 1.25 to 1.5 D range there is minimal impact on the ability of the brain to blend the two images. In the past some have used full monovsion with anisometropia in the 2.0+ range. This gives better reading, but at a cost. This practice has been pretty much abandoned in favour of mini monovsion (1.25 to 1.50 differential).
- With MF and EDOF lenses you kind of roll the dice and hope to get what you expect. If you do not and are unhappy with the outcome, it may be more difficult to correct the issues with eyeglasses. You can't get eyeglasses that will undo the multiple focal points built into a MF lens, or unsmear the stretched focal point of an EDOF. However when you use monofocal lenses to do monovision your eyes are easily correctable with eyeglasses. Prescription glasses are always a safe plan B that can be counted on.
.
Summary
My experience is that Mini Monovision is one of the "Best Kept Secrets" in the Ophthalmology field. Some can't be bothered to tell you about it. Some don't seem to know much about it. Some don't want to be under pressure to hit a specific target for myopia in the near eye. And, unfortunately some only want to do premium lenses with their associated higher profit margins.
.
I would suggest if you are interested in mini-monovision there are a couple of critical questions to ask when looking for a surgeon. One of course is to ask if the surgeon does monovision and is willing to work with you on it. The other is to ask what brand and type of lenses does the surgeon use. Some a locked into one specific manufacturer, and others are locked into premium lenses only.
.
And for those that suggest monovision is unnatural consider that man has been around for about 200,000 years, while eyeglass correction has only been available for less than 1,000 years. Our brain has evolved to use the images from two eyes and put them together for the best combined image. And also consider that it is not only used for IOLs, but it is also commonly used with contacts, and also with Lasik surgery to get closer vision. They don't use Lasik to give you a multifocal eye, they use it to give you monovision using two eyes.
.
I hope that helps some, for those who are considering this Best Kept Secret option for IOLs.
11 likes, 250 replies
Lynda111 RonAKA
Edited
Well said, Ron.
I have posted numerous studies on another thread about good outcomes with mini-monovision. Here is one more:
Journal of Cataract and Refractive Surgery, 2022. " Ten Year Outcomes of Pseudo-phakic mini-monovison"
Over 10 years, 463 patients who underwent cataract surgery with bilateral mini-monovision using monofocal IOLs were observed. The conclusion was that mini-monovision is a" safe, effective and low cost approach for long term correction of presbyopia. It significantly reduces spectacle dependence and fulfils patients' expectations after bilateral cataract surgery."
Mini-monovison is not for everyone. But it works well for many patients.
wicca08726 Lynda111
Posted
Hi Linda,
For what patients it does not work? Do you know?
RebDovid wicca08726
Edited
While I can't give an exhaustive answer, I can say that monovision doesn't work for people who don't adapt well to it, for example, because the difference between the two eyes induces headaches. (It also may not be a good idea for people with certain conditions, but I can't really speak to that.) Observationally, according to various accounts, a differential between the eyes of up to 1.5 D, referred to either as mini-monovision or subdivided further between mini- and micro-monovision, is tolerated well by most people.
.
But this is only a general observation. That's why, to be prudent, many people recommend trialing monovision with contact lenses before cataract surgery. If it works for you at a particular differential, then, I suggest, either ask your surgeon to target a somewhat smaller differential to leave room for refractive surprise or try again with somewhat larger differentials until you reach your limit (and then ask your surgeon to target a differential comfortably below that differential).
karbonbee RebDovid
Edited
There is a difference between "monovision" and "mini-monovision". With mini-monovision care is given to make sure that the final visual outcomes of each eye stay with a certain range of each other, so the vision overlaps between both eyes, as opposed to standard monovision where the target is just for near and distant. That mini-monovision overlap is also easier for people's brains adjust to, as it's not either/or. For myself, I had no experience with any real degree of monovision of any type, yet I now have no problems at all adjusting with a difference of 1.0D between both eyes. And because both the vision of both eyes are within range of each other, they work beautifully together, giving me full blended vision with no idea of what each eye is doing -- thus, no stress for the brain. No problem with depth perception either, although I'm sure the bully birds at my feeders wish there was as I'm now nicking their evil little butts with even more accuracy while using smaller ammo (no kill clay pellets).
RebDovid karbonbee
Edited
I'm well aware of the distinction between monovision and mini-monovision, as well as the usage by some of the additional term micro-monovision. And I agree that as the difference in diopters between the eyes goes down the likelihood of successful accommodation goes up. BUT it's only a likelihood. We are all ourselves. Some of us will be able to accommodate a greater degree of monovision, some of us less. That's why, if at all possible, I think it makes sense to try monovision with contacts lenses before attempting it with IOLs. It's also why, for myself, my thinking is to ask the surgeon to target a difference 0.25 - 0.50 D less than my successful trial.
RebDovid Lynda111
Posted
According to the "Ten Year" article's abstract, which is all I can access, the study was of patients treated for hyperopic presbyopia. Unless the shape of the eye might cause different results, I don't know why mini-monovision should be less successful for emmetropic and myopic patients. But I do think it important to note the study's self-described limitation.
stefan64833 RonAKA
Edited
Monovision or mini-mono is an induced IOL implantation technique that creates nearsightedness in one eye purposely for reducing dependency on spectacles after cataract surgery. It can offer a potential safe and effective approach in the right patients, so it’s not a one size fits all model. Early presbyopes may be candidates for monovision as an alternative method to other intraocular lenses (IOLs) used for treating presbyopia.
However, the better you make your distance vision the worse you make your near, and vice versa. The greater you make the monovision (mini) dioptric power difference, the greater the image differences (blurred) being presented to the brain, thus increasing greater chances that they may not be able handle the image differences creating problems in contrast sensitivity, stereopsis, and binocular visual acuity. Remember, no two patients are alike. A person’s occupation and daily activities may also make them think twice about this procedure.
Like other IOL patient selection, equal attention is required for the proper selection of traditional monovision or mini-monovision candidates factoring the surgeon’s confidence & ability to achieve intended refractive goals based on patient corneal irregularities, ocular pathology, the aberration profile of the selected IOL and patient tolerance to neuroadaptive, depth of field, & visual acuity issues. Execution of mono or mini-monovision is not without its own risks.
Surgeon’s will likely have an opinion on this approach based upon their own already established views, experiences, and habits. If a surgeon is not convinced of the benefit risk ratio over other available options themselves, a patient will likely need to go somewhere else.
As with all implants, monovision (mini) patients may need glasses for fine print or for night driving.
RonAKA stefan64833
Edited
There are risks with all IOLs used for cataract surgery. It is my opinion based on personal experience and research that I have done, these risks are much lower with a monofocal mini-monovision solution than a multifocal IOL solution. And the advantage of a monofocal mini-monovison solution is that it is easy to correct any residual refraction error with eyeglasses if necessary. The distortion of the optical characteristics introduced by a MF or EDOF lens are not reversible with eyeglass lenses. And some MF IOLs like the Lenstec ClearView 3 are even more difficult to deal with for both the brain, and for eyeglass correction. This lens induces a gross amount of astigmatism (3.0 D) in a full semicircle of the lens. Normal astigmatism is in quadrants, not a semicircle. This is very unnatural for the eye and brain to deal with. This contrasts with a monovision solution where there is some mild anisometropia between the eyes, which is a very common issue and occurs naturally all the time.
.
This said there are a lot of people that are at least somewhat happy with MF IOL solutions. My point is that the risk level of not liking it, or not being able to deal with it, is much higher than with mini-monovision.
.
The lowest risk of course is to use monofocal IOLs both set for the same focus point; near, intermediate, or far. But, each of these will not be an eyeglass free solution.
RonAKA stefan64833
Posted
I should add that when you have astigmatism that is only on one side of the cornea and is not a symmetrical hour glass shape over two opposite quadrants, it is then called irregular astigmatism, and can be caused by a condition called keratoconus which is a thinning of the cornea that causes it to bulge in an irregular manner. So it does happen in real eyes, but it is far from being considered as a good condition. I have irregular astigmatism in one eye in the order of 0.75 D. It causes me to have a drop shadow double vision in this eye. So this IOL is not only inducing astigmatism, it is of the irregular astigmatism type. I would worry about it causing double vision issues like I have.
neverquit RonAKA
Edited
From buying a new smartphone to windows11 or a new car, i made it a steady habit in my life to never buy the newest model of anything, that just came to market, and therefore avoid being essentially the guinea pig for the producers.
Seems to me, that this mindset would be advisable especially with new IOLs as well. I would wait for many experiences and reviews from others, before actually considering it for myself.
karbonbee neverquit
Edited
Yes, but you also have to remember that many of the "newer" IOLs in North America have already been used for a couple of years in Europe and other countries. So when researching them, it is good to check out results from non NA areas so you get a fuller picture.
billy111 RonAKA
Edited
Both you and Stefan make good points about mini-monovision. Premium IOLs continue to evolve and improve. Over time, they will undoubtedly have fewer risks and side effects than they do now. But for many people, particularly those patients who cannot afford the $2,500 cost of a premium IOL per eye, or who are not good candidates for a premium IOL, or who are risk-averse to optical side effects, mini-monovision may be the best choice for them.
Or maybe the safest choice of all (because you can't replace an IOL as easily as you can spectacles), is just to aim for distance, intermediate or near with a monofocal and wear spectacles or readers if you still need further correction. It is an individual choice.
stefan64833 billy111
Edited
What they don’t tell you is:
A key deciding factor between a presbyopia-correcting IOL and pseudophakic monovision is the patient’s level of motivation for achieving spectacle independence not optimized restorative vision acuity.
If you require crisp, detailed vision, then the monovision cataract surgery is not the best option for your needs.
Most people who have monovision will typically still have to wear glasses for driving, especially during the nighttime hours.
Even though a lot of people do eventually get used to monovision, some struggle to adjust well to the outcome of their surgery. The brain can struggle to process the two different information images that it receives from both eyes based upon different focal points, which means you could end up with vision problems which are worse than they were before.
Physicians rarely perform a monovision cataract surgery on patients who must have a high level of stereo acuity needs. If you are at a high risk for falling or do not get around very well, then the changes to your depth perception could be enough that it creates disorientation. Anyone who needs to have these vision elements for their work, including police officers, truck drivers, and pilots are not good candidates for the procedure. Certain hobbies, such as tennis or golf, could be problematic as well.
When it comes to monovision, the best way to determine if it’s a good fit for you is to talk to your optometrist and consider giving it a test run.
billy111 stefan64833
Posted
You just now replied to a 5 week old post ? In any case, yes, cataract surgeons often do not fully explain to patients all of their options . I would advise patients to get different opinions and explore their options. Mini-monovision works well for many people but it's not for everyone. It's best to try it out with contacts first. I myself choose binocular intermediate vision (my job involves computers) and to my cataract surgeon's surprise, ended up with excellent distant and intermediate vision and good near vision. The refractive outcome of cataract surgery depends on a number of factors and can vary from patient to patient.
RonAKA stefan64833
Edited
I do agree with this statement.
.
"When it comes to monovision, the best way to determine if it’s a good fit for you is to talk to your optometrist and consider giving it a test run."
.
The rest of your post I would suggest is ill informed opinion on your part. The reality is there is no perfect IOL solution with cataract surgery. There are risks with all options. With the eyeglass free options I would suggest the options in order of risk from highest to lowest are: