Monofocal lens set for near vision

thx for the input. what do you mean by "mini monovision"? is it the different number iol for each eye?

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.

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

Yes you will lose it. My clear -2.5 vision starts at about 10".

bookwoman, did you get a monofocal lens? and what do you mean by "-2.5" vision?

sorry if these questions appear to seem clueless but i need to ask lots of them.thx

No worries - questions are good! I got both eyes done with monofocal, -2 lenses. The one in my left eye settled so that my vision there is -2.5, in other words, a bit more myopic than the -2 in my right eye. So if I cover my right eye, my left eye sees perfectly clearly beginning at about 10". For my right eye alone it's 14".

With both eyes together perfection begins at 12" and extends to about 24". Beyond that I can still see objects just fine, and even read large titles on the books about 3 feet away from where I'm sitting, although of course they're slightly blurry.

I never wear my eyeglasses and don't know much about prescriptions. What is -2 lenses for your monofocals. How does that compare with eye glass prescription?.

Intermediate is supposed to be 20 to 40 inches. I did not know near was from 10 to 30? It overlaps with intermediate. My eye doctor thought intermediate a good choice for my monofocals but I am unsure? I have decent near and far vision right now.

It will be difficult to have worse vision in 2 areas.

Spring

I had both of my Tecnis I monofocal IOLs set for intermediate vision. I have 20/20 distant vision and I can read the computer very well. For sustained book reading I will use readers, but sometimes in bright light, I don't even need readers. I think intermediate is a good choice. At least it was for me.

Finally someone who has had monofocals set at intermediate. You actually have good distance as well since intermediate ends at 40 inches? I am surprised at that?? Also, it beings at 20 inches so close up should be har also??. When you say readers, what do you mean? Reading glasses? I use a chromebook to read books and it is great. Never touch glasses!

With the intermediate focus, though, I am surprised that you are getting improvement in distance and close up as well? Why would that be?

Why would that be? Because defocus curves, whether they tell us explicitly or not, represent an average of the results from the total number of eyes examined. The actual results are more spread out. Any one of us can end up above or below the logMAR line shown on a simple defocus curve graph.

Also, personal factors, such as pupil size, may play a role in determining an IOL's results when implanted in our eyes.

In considering the focal point at which you want your surgeon to aim, you may want to search on line--directly and through your library, if it makes ejournals available--for articles containing defocus curves. Generally, they also will show a standard deviation and may even depict the standard deviation above and below the defocus curve itself.

Although nothing is guaranteed, the most prudent courses seem to me to be either to trust completely in your surgeon's judgment, after having one or more good discussions about what you're trying to achieve and what you want to avoid, or search out defocus curves, average them together, and take the results as indicative of where you're likely, but not guaranteed, to end up if your surgeon hits the target.

Finally, just in case it's helpful, note, although the defocus curve may show only a single line assuming a 0.0D focal target, you can use the curve presented to derive other curves. For a -1.0D target, for example, move the curve two positions to the right. For a -0.25D target, eyeball the point on the curve half-way between 0.0D and -0.50D, -0.50D and -1.00D, etc.

Yes, reading glasses. My vision after cataract surgery surprised me and my surgeon. I had 2 diopeters of astigmatism prior to surgery, which I did not correct with a toric lens or with limbal relaxing incisions. My surgeon said something about when she set the IOL for intermediate the axis it fell on took away a lot of my astigmatism. Or something to that effect. But as I have said before , no two people have the same eyes. And what happened to me may not happen to you. There are a lot of variables involved.

The consensus on this forum seems to be to opt for mini-monovision. It works well for about 75% of patients. It is best to try it first with contacts. I have read also that it is not suited for people who tend to be extremely aware of bodily sensations, as I am. I am glad I chose intermediate and used the Tecnis 1.

Very interesting! Maybe you had good luck? Mini microvision working for 75% is not really good enough numbers for me. What happens to the 25% or one in 5. Too high of risk. I will talk to the surgeon on Tues day and see what she says. I have AMD so I need to probe that issue more and why she suggested intermediate.

The backup plan for most cataract surgeries is simply wearing glasses. With mini-monovision the under correction in the near eye can be fully corrected with glasses. The other less attractive option is to have the lens explanted and replaced with another lens. Some may choose to have a correction made with Lasik. And last there is another option of having a piggyback lens implanted that further corrects the vision.

.

Cataract surgery is not a risk free procedure. Accuracy of hitting the intended refraction goal is not all that good either. About 75% of the time they are within +/- 0.5 D of the targeted goal. That is why it is good to target a range rather than a specific diopter target. So called refractive "surprises" are not all that uncommon.

Can I ask what you mean by targeting a range rather than a specific diopter target?

I forgot to ask why did you and your surgeon select the intremediate range rather than distance which is the most common choice?

I might look into that later. Thanks.

For example the ideal diopter target for the near eye in mini-monovision may be -1.50 D. The more reasonable target would be the range between -1.25 D and -1.50 D. Because IOLs come in fairly large 0.5 D steps of power, there is almost always a decision between two lens powers to be made.

I. chose intermediate vision because my work requires me to be on a computer 8 hrs a day. So it was important I have good intermediate vision. My surgeon agreed with my choice. But in your case your surgeon recommends it. No one here is. a cataract surgeon and no knows your eyes like she does. You can always get a second opinion if you wish with another cataract surgeon.

Lynda,

I know you said intermediate but what was your targeted IOL and what did you end up with?

When you say intermediate, what did you end up with for residual sphere and cylinder in diopters for each of your eyes? i.e. your eyeglass prescription to correct you to plano?

I just told her tech to fix the IOL. distance my arms length.

The IOL card I was given after surgery says left eye 15.50

right eye 16.50

Ron

I have a Rx but never filled it.

It says Right eye Sphere +0.00 Cylinder -1.25

Left eye Sphere+0.25,Cylinder -2.25

Thanks Lynda!

I know everyone's eyes are different and everyone may not get the same results as you as you caution but still great info to have.

Ron are you able to convert those numbers (15.50 and 16.50) to approximate diopters?

On a sphere basis only without considering astigmatism you are essentially plano or full distance in both eyes (well, very mildly far sighted in the left eye). However, on a spherical equivalent basis which tries to approximate the impact of the astigmatism and convert it to sphere (by counting 50% of it) this works out to be:

.

Right eye SE: -0.625 D, peak visual acuity at about 60"

Left eye SE: -0.875 D, peak visual acuity at about 45"

.

So you are getting all your nearer vision from the astigmatism.

The power of the lenses can't really be used to determine where the eye is now, without knowing where it was before surgery. On a rough basis a lens power of about 18.5 D is used for someone that was plano before surgery and wants to remain plano. Less than 18.5 D means myopia prior to surgery. I would guess around -3.0 in the left and -2.0 in the right.

.

But, to answer your question as to where the eyes are now, see my previous post. There is significant residual astigmatism but on a spherical equivalent basis about -0.6 D in the right eye, and -0.9 D in the left eye.

.

I think this illustrates that astigmatism can be used to give some EDOF effect.

Honestly, I use the computer a lot also but I think that is near vision and not intermediate which is 20 to 40 inches? I don't gey it? Are the ranges not really reliable or accurate? Would I have good near vision if I get intermediate? There is hardly anyting that I do that is between 20 and 40 inches but lots that is near and far. I defintely will not make a decision without all the input from my doctor or a second opinion, btw. I am very careful but I dont' really do much in the intermediate zone....again unless those ranges are flexible and cover other areas. This is all very confusing and difficult! Thanks!

I never wear glasses and can barely read this prescription. I guess that means your near vision is excellent and your distance is a problem specially in the left eye?

Since I haven't seen diopter's before....does that mean the same as reading glasses for near vision in the near eye at +1.50 for a prescription?

Ron,

You say I am getting my near vision from my astigmatism? Well, I guess it's a good thing I didn't try to treat it with a toric or LRI's.

When I first saw my cataract surgeon, (she did my left eye first) she told me that since I had been myopic all my life I should stay that way,. She said after cataract surgery I would still need glasses but the lenses wouldn't be as thick as what I was wearing. To preserve my good near vision, she wanted my IOL set for near. But as i have said, I told her to set it for intermediate and she agreed. A few weeks later when she did my right eye, she again asked me if I wanted the IOL set for near and I said no, set the right eye for intermediate so that I will have binocular vision. She agreed.

And that's how I see as well as I do.

As I've said before my cataract surgeon and I were both surprised that I really didn;t need glasses after all, except readers for sustained reading if the lighting is not really bright.

The more accurate way to specify range of vision is to use diopters. These are the corrections required if you were to get eyeglasses. Some examples would be 0.0 D for full distance, -1.0 D for 1 meter peak vision, -2.0 D for one half a meter, and -3.0 D for 1/3 meter. You just divide 1 meter by the diopter to get the distance. To compare to readers +3.0 D readers when you have plano vision would be the same as being left at -3.0 D.

If you have perfect distance vision and put on a pair of +1.5 D readers that is the same as being left needed a correction of -1.5 D to bring your vision back to plano. Or in other words -1.5 D near sighted or myopic. The peak vision if you are left at -1.5 D would be at 1 meter divided by 1.5 or 66 cm. But keep in mind that while peak vision is at 66 cm, you will still be able to see a range around that. I can see down to about 10" reasonably well with about -1.5 D vision.

Is that because you had really good near vision already? I wouldn't think that would make a difference because they remove your flexible natural lens and the iol is not flex so all it would give you is the intermed. at 20 to 40 inches? Perplexing your situation is and I wouldn't think this would apply to everyone. I now have great near computer vision which i would hate to lose. Never use glasses except for fine or faint print. My distance is not great but honestly don't need glasses for driving since the signs are large...dim light is a problem but then i have intermediate dry maciular degen. I don't have a clue what i would end up with getting intermed as a focus. Someone said i would have to then use near glasses at 2.5 which sounds disastrous for me since i wear 1 and 1.25 rarely.

Actually they could have used a toric IOL to reduce the astigmatism (cylinder) significantly. If you wanted to remain at intermediate then an adjustment to the sphere power would have to be made. Right now if you could magically get rid of all your astigmatism your would have nearly perfect distance vision, and very poor near vision. To get back to where you are they would probably have to use a IOL power that was about 1.0 D greater. Reducing astigmatism would likely increase clarity but also reduce the range of vision you now have.

Unfortunately, with my lack of glasses experience (I avoid the prescriptions and use my own eyes)....this is all greek to me and I would have to get some more instruction on it. Thanks for trying to shed light on it. I do now know what the word plano means! That is the good news! Thanks again!

Is the +1.5 D the same as the prescription I have for reading glasses at 1.50 spherical which is a not too terribly strong pair of reading glasses but for me is strong since I always used +1.00?

If you have good or close to plano vision and put on a pair of +1.5 D glasses to read, that essentially simulates being -1.5 D myopic. If you got an IOL and asked to be left -1.5 D myopic in one eye, that is the reading vision you would get.