hi guys. im curious as to why i never hear of people getting a monofocal vision set for near instead of for far. for myopes, the pleasure of not needing glasses to drive etc would perhaps be outweighed by having less of an adjustment to just put glasses on to see for intermediate and far, as we all have been doing that for as long as we had myopia. is there a down side to getting a close monofocal lens? thoughts? also, for those who have gotten monofocal implants set for far distance, at about what distance from your eyes does your vision begin to get blurry as you get nearer something? thanx much. trying to amass info for the future dan
We're few and far between, but we exist! I had -2 monofocals implanted 3+ years ago. One wound up at -2.5, so I have mini-monovision and it's worked out really well for me. I was a high myope before (-8 in both eyes), I spend much of my time reading or on the computer, and didn't want to lose my close vision. Now I only wear glasses when I go out or when watching TV, and my vision overall is better than it's been since I was a child. Since most people want distance vision for driving and/or sports, a lot of ophthalmologists just assume that everyone wants it. But since we myopes have never had distance vision in the first place, there's nothing to miss, and getting near-vision IOLs will, as my surgeon put it, make our brains happier.
because setting for near will give very limited range. like 14 to 30 inches. if you go that route vivity or eyhance could be better option.
soks, yes, perfect vision is in that range, but usable vision extends much further. It's not like everything is suddenly completely blurry after 2 feet, it's just a bit fuzzier.
dapper There are many posts on this site about near/ intermediate vision. In my case, I specifically said I wanted intermediate or computer vision in both eyes and it worked out better than I or my cataract surgeon expected. I have 20/20 distant vision, excellent intermediate vision, and I can read my cellphone and depending on the light and font size, can read fairly well. I do sometimes use readers. And I see this well despite having 2D of astigmatism prior to surgery that was not corrected by a toric iol or limbal relaxing incisions. My surgeon said that because of the axis, targeting both eyes for intermediate reduced my astigmatism. But remember, all eyes are different. What worked for me may not work for others.
I should add that many patients and cataract surgeons think only about near or distance vision. They forget the third option: intermediate vision.
Such an important topic!
DapperDan: You say you "see this well despite 2D of astigmatism." It might be that you see that well BECAUSE of 2d of astigmatism (and perhaps higher-order aberrations in your cornea). Uncorrected astigmatism and higher order aberrations gives one greater depth of focus, albeit a softer focus.
Here is a quote from one scholarly article I found online: "It is known that the MTF of an unaberrated eye shows greater sensitivity to defocus than an optical system with aberrations. Although, these aberrations compromise the MTF at best-focus, they increase its relative measure with defocus and, therefore, result in a higher DoF.5 "
You can pull up the article by using a snippet of that paragraph in your search string.
One of the ways that you can get extended depth of focus in an IOL is through manipulation of spherical aberrations introduced into the lens on purpose. They do this with the light adjusting lens, for example, if you request it.
I am a high myope with extreme astigmatism and other aberrations in my cornea. My right glassis lens has 8.25 cylinder. I discovered that reducing my glasses prescription by 0.75 diopter (absolute value) on the sphere in both lenses gives me an incredibly versatile pair of glasses. I can read my phone, use my computer and drive, all with one set of monofocal glasses. And yet I am 73 and have cataracts, so almost certainly hardly any accomodation left.
This versatility is apparently a result of the corneal aberrations. I recently got scleral contacts in order to do experiments to see what targets I wanted for my cataract surgery. Sclerals are a hard contact lens that eliminate the effect of all aberations. I was thrilled by the sharp vision, and shocked by the loss of depth of focus. I got the contacts set for reading distance. I need glasses to do ANYTHING other than read normal-size print at about a foot, once I put the contacts in. Worse, I need 3 sets of glasses -- one to read tiny print, another to work on the computer, and a third set to see the TV or drive.
This is one big reason why people's experience with the same IOL varies so greatly. They have different corneas! You can't base your expectations for depth of focus on anyone else's experience unless you know your corneas are shaped like theirs!
I had asked for my contacts to be set to -2.75, which I had determined to be the value I need for reading tiny print. I believe they missed that target and I am at -2.00. I have glasses with -2.75 lenses and another set with -2.00 lenses. Distance vision is better with the -2.00 pair. In fact, vision is better at all distances with the -2.00 pair than with the -2.75 pair. To read tiny print with the contacts, I need +0.75 lenses.
I had thought I would want my IOLs targeted to something like -2.00 or -2.75. But now each time I put in my contacts, I am so thrilled to see the table I am sitting at so clearly without glasses -- and so disappointed when I look up from the table at something across the room. I am coming around to thinking I want to target -0.75 and get glasses-free vision for my most frequently used distances. I will gudgingly get readers for tiny print and close work in my workshop.
An interesting byproduct of all my research with glasses of different powers and contact lenses is I discovered I can put off cataract surgery. I still CAN get 20/20 vision -- or close to it . I just have to use different glasses than I was prescribed. My complaints about vision with glasses were entirely based on not being able to use my computer comfortably with progressives. Once I threw away the progressives and started ordering monofocal glasses with different sphere powers, my problem was solved. My optometrist and ophthalmologist had told me I needed cataract surgery. But I have concluded I don't. Not yet.
I highly recommend experiments with contacts and cheap on-line prescription glasses as a way to determine what IOL targets you want. It's not a perfect method, because the contacts counteract your cornea's spherical aberrations and reduce your depth of focus. What you see with your natural lens and your corneas plus contacts is going to be different from what you will see with IOLs and just your corneas at the corneal plane. The depth of focus and the sharpness will both be different. But still, it's educational to experience different glasses-free vision, and mini monovision, and different strategies with glasses. I now have many pairs of glasses of different powers ordered at $20 - $25 each from Zenni Optical, that I can only use with contacts.
Soft contacts don't work for me (they make my vision worse, not better) but most people can use cheap dispoable soft contacts for experimentation. Just get your eye doc to give you prescriptions for the different targets you want to try. Sclerals are great, but they cost thousands of dollars. For me, they are covered by insurance because of my weird corneas (keratoconus).
Most cataract surgeons seem to have a bias against setting both eyes for near. They prefer a monovision approach for patients that wish to retain some degree of near vision.
I believe that's because people like us who do our homework, ask a lot of questions, and are capable of making informed decisions when it comes to cataract surgery are few and far between. I think most patients have no clue, so the surgeon is going to recommend the best option based on their individual experience with patient satisfaction.
So my take is that the only reason there aren't more patients who choose to target intermediate or near is because those patients who do so tend to be far better informed and more self aware than the average cataract patient.
Even within that pool of informed patients,, I think setting both eyes for distance or taking a monovision approach would still be the most popular option, but the numbers wouldn't be as skewed as they are in comparison to the general population..
thx for the input. what do you mean by "mini monovision"? is it the different number iol for each eye?
im curious if even with both iols set for near, will i lose the ability to see at very close range (6" or less) like i can do now?
thx for the input
hi lynda. so did you get multifocal IOLs to achieve that good vision at far, intermediate and near?
thx for any input
hey thomas. great post. it boggles my mind that people would NOT do their homework with their most precious sense: vision. i have been doing my due diligence for awhile. one thing i have learned in seeing several optometrists is a lack of patience and unwillingness to volunteer information to a patient asking many important questions. i will never chose a doctor who withholds info or makes me feel i am a burden by seeking info.
i have another appointment at the end of the month and after discovering this site all the great info, opinions and caveats, i realize i need to do even more research before proceeding so thanks to all who share info and experiences
Yes you will lose it. My clear -2.5 vision starts at about 10".
Yes, that's generally how the term is used, although in my case it came about because of the way the -2 IOL settled in my left eye, making it -2.5. (Which is something to bear in mind - what is targeted may not be what you wind up with.) Many people have two different diopter IOLs put in so as to extend their range of vision. RonAKA is our resident monovision expert, so you may want to read some of his posts.
There is nothing wrong with getting both eyes set for close distance. For sure you will have to get prescription glasses to see well in the distance and drive. And if you don't want to keep taking your glasses on and off you will need bifocals or progressives. The other minor issue is that your glasses will be a bit thicker than if your eyes are corrected for distance. . If you have the lenses set for distance you may be able to get away with OTC readers instead of prescription glasses. But, cataract surgery is not as precise as eyeglasses and to get the best vision it may be worthwhile to get prescription, to correct any unexpected residual error in sphere and cylinder. . My solution to this is to get one eye for distance and the other to see close (target -1.5 D). I like it a lot and almost never wear glasses. For very small print in dimmer light I will occasionally use some +1.25 readers. And for the best vision at night out in the country I have some prescription progressives that I will use. . On my eye set for distance (0.00 sphere, -0.50 cylinder) I can see a computer monitor down to about 18", although that seems better than average. 2-2.5 feet may be more typical. One my close eye I have astigmatism issues and is not the ideal -1.5 D sphere. I am at -1.0 D sphere and -0.75 D cylinder. The spherical equivalent of this is about -1.40 D. I can't see as close as when I was quite myopic in the -3.0 D range, but I can see to 10" or so in good light. For real close I use some stronger readers or my progressives. . You say you are doing your research for the future. The one bit of advice I would give you if mini-monovision is of interest is to do a trial now using contacts. Target plano distance in the dominant eye, and -1.5 D in the non-dominant. The catch 22 that many of us get into is that we let the cataract progress to point where it is difficult to do a contact trial where the results are hard to evaluate due to the cataract impairing vision.
great info and advice jim!
so im assuming you are still experimenting and have not gotten the surgery yet correct?
im having a more difficult time driving at night because of the glares, halos etc. but not sure that is a good enough reason to proceed. outside of floaters and all the normal age related stuff like presbyopia, i still see ok. i worry that all the people who are extremely happy and relieved after surgery had such bad vision that ANYTHING would be an improvement. im certainly not there. i need to understand more of what you are explaining about experimenting before i dive in. i cant afford scleral contacts but seems like a good idea to do more research.thanks. ill likely ask more questions very soon.dan
Dapper No multifocal. I had a standard Tecnis 1 piece monofocal IOL in both eyes
Yes, do research. And not just on cataracts. Do research on all medical issues, if at all possible . This forum was very helpful. Cornea/Anterior Segment ophthalmologists are specialists in cataract surgery. See more than one, even if you have to travel.
With all that said, most cataract surgeries do turn out well for most patients. New technology will only make cataract surgery better in the future.
with +2.5 glasses on my symfony eye it is suddenly blurry after a foot. so with iol it nay be differenr than glasses.
Upon being diagnosed with cataracts, but prior to meeting with my surgeon for the first time, I thought "Oh, okay. They're going to replace my natural cloudy lens with an artificial lens, I'll have 20/20 vision for the first time since I was a teenager, and it's covered by my insurance. Wheee!"
Then I met with my surgeon for the first time and he explained to me that due to my astigmatism, I would likely need to wear corrective lenses for most daily activities after the surgery. (This was after I informed him that I wasn't considering laser assisted surgery to correct my astigmatism or premium lenses.)
Wait. Hold up. I'm getting cataract surgery, and my eyesight is going to be WORSE than it was before the cataracts developed? I still had excellent intermediate and near vision prior to the cataracts, and while my distance vision was definitely below average, it was good enough that I could get by without wearing corrective lenses. I was very upset.
That's when I began taking this seriously and became obsessed with learning as much about cataracts, cataract surgeries, and lens options as possible. Forget what insurance covers. I'm going to have to live with this decision every waking moment for the rest of my life, and I'm only 56. Now every option was on the table.
I scheduled a second consultation with my eye surgeon. This time I was I was fairly well informed, and he and his assistant were the polar opposites of impatient and unwilling to volunteer information. They loved me. That's when I began to appreciate what it must be like to be on their side of the fence and have to try to explain something this complex to clueless patients (like I was on my first visit) every day, day in and day out.
My point being that if your surgeon doesn't appreciate you taking a vested interest in your cataract surgery and asking thoughtful and intelligent questions, you've got the wrong surgeon. If they're truly passionate about what they do, you should be one of the highlights of their day, and maybe even their entire week...and vice versa. I'm actually going to be a little sad when this is all over and I don't have any more appointments with my surgeon. He's been awesome to work with.