Near vs. intermediate setting for IOLs

I think what happens is that some people get drawn in by IOL company marketing. They promote the Vivity for example which gives an extra 0.5 D of nearer vision (into the intermediate range) and sell the lens at a substantial price premium. But, you can get an extra 0.75 D of intermediate by simply using a monofocal set to -0.75 D in your non dominant eye. It is called micro monovision. The extra cost is nothing, and there are no risks of the optical side effects of EDOF lenses. It is the same issue with the Eyhance. If you want the very minor gain which many not even be statistically significant, then just do the non dominant eye at -0.5 D instead of the usual -0.25 D.

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The problem of course with doing these intermediate only improvements is that they still do not give you true reading vision. To do that you need mini-monovision at -1.50 D in the near eye.

Well, Ron, as you may remember, I told my surgeon I wanted the Tecnis 1 set for intermediate vision (computer distance) in both eyes and I ended up with excellent distance and intermediate vision and good/fair close near vision. My 2D of uncorrected astigmatism helped, the axis fell on the right spot and well, I got lucky. I was myopic all my life, and both my cataract surgeon and I fully expected I would still need to wear eyeglasses after surgery, but just not so high-powered. We were both pleasantly surprised by the outcome, which only goes to show that refractive outcomes are hard to predict and can vary from person to person.

Hi Lynda111, Thanks! I've googled "Importance of intermediate vision" and do find many interesting titles. More homework prior to my next cataract surgery appointment!

so when you do something like -.5 or -.25 on the dominant eye and a -1.75 on the near, the overlap will completely cover the intermediate. correct?

can you explain what "The axis falling on the right spot means"? im confused how an asymetrical cornea helps vision in any way. any help is much appreciated

With a monofocal you likely can get away with -1.75, but that is starting to push it. Have a look at the figures in this article. Figure 2 displays the binocular visual acuity with -1.0 D, -1.5 D, and -2.0 D in the near eye. With 2.0 there is starting to be a dip at the 2-3 foot mark. Targeting -1.5 D is safer, but it you get -1.75 instead, it is not likely to be a disaster.

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Optimal amount of anisometropia for pseudophakic monovision. Ken Hayashi, Motoaki Yoshida, +1 author H. Hayashi Published 1 May 2011 Medicine Journal of refractive surgery

Hi Ron, I've been pondering this very scenario.

I've been considering asking for what might be considered mini or micro monovision. For example, having near eye targeted for either -1.75D or -1.5D and depending on the results, going an extra -.25D toward distance for the distance eye? Would that be too small a range between the two eyes to make a difference? Thank you!

I think the issue with both eyes set so close together is that it is not going to give you a much wider depth of vision, and you still will not have distance and will need glasses for that. If seeing near without glasses is a priority then I would be tempted to stay at -1.75 D or -2.0 D.

I have -0.5 distance and -1.75 near. No noticeable dropoff of vision quality at intermediate distances.

Hi Lucy--- You are able to tolearate that much between eyes. Are you experienced with mono vision contact lenses though this is moderate monovision. ? Was this plain monofocal or edof lens?

Are you able to see computer clearly and work on it at about 24-26 inches .WHat is smallest print you can see without glasses?

I maybe getting the EMV -Only one eye now since doctor said not ready other eye and won't do it till ready so the target would be-1.50 and of course can settle to something else. I wouldn't aim for more than 1 between eyes when time for second eye WIth the emv supposedly the technogology if hit -1.50 may let my eye see at about -2 to -2.25 which I hope is correct so can go for more disance in second eye.

Love to get feedback with your combo of eyes where you need to put on glasses and how eyes work together to see things

Hi loveanimals,

I had about 40 years practice with naturally occurring monovision with very similar measurements, so this was a piece of cake--it just feels normal, although I do miss the little bit of accommodation I had left. I saw one doctor who didn't want to do monovision without a contact lens test even though it's what I'm used to--needless to say I changed doctors (my cataracts were too bad to do a test.) If you look earlier in this thread I wrote up what I could see on a Jaeger chart and when I wear glasses. I normally sit about 20" from the computer and it's crystal clear. 24-26 inches wouldn't be a problem except with my current desk setup I wouldn't be able to reach the keyboard. Small print depends somewhat on the color and font used and the distance at which I'm reading. I can see the J1 of the Jaegar chart within arms length with my near eye--can move it a little closer when using both eyes, so for most quick reads--envelopes, recipes, etc I don't use glasses. Prescription medicine inserts in blue text on off-white paper with teeny font requires glasses. High contrast is better, probably in part because I've got PCO. I've got Tecnis ZCB00 monofocals.

When I looked at defocus curves before surgery, this combination of lenses looked like it would result in roughly 20/25 vision from about 17" to infinity, and dropped off with near vision, dropping below 20/32 at about 15" and below 20/40 at about 14" for a conservative curve. This appears to match well with the my results. My doctor nailed the targets. (He did use ORA, so that might have helped.) If I'd known what a good job he'd do at hitting the target, I might have gone to -2.0 for my near eye, but -1.75 was a little more conservative in case of a miss. Things are easier now that I've gotten used to moving something away rather than nearer to see it more clearly.

can you explain how 2d of astigmatism "helps" and what the "axis falling on the right spot" means? thx

Dapper,

I am going to send you a Message. AKARon explained to it by Message and I will see if I can cut and paste it to you. If not, he could do a better job of explaining it than I.

Dapper, I cut and pasted it to you. Check your message box.

**Well, I don't think Ron would mine if I shared his message. What he said may help others."

"Astigmatism is tricky. Think of your eye as a pie cut into 4 pieces. Now look at two diagonally opposite pieces, and consider them set for more distance, while the other two pieces of pie diagonally opposite are set for nearer vision. The pie overall in your case is set for intermediate distance on average, but the individual segments are set for nearer and further. If, and it is a really big IF, you brain can make sense of those different focus images and put them together then you have a wide range of vision. It sounds like you can.

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As I recall your surgeon corrected your sphere vision to plano and left the astigmatism to deal with near. You had a good outcome. I would guess that the backup plan would have been that if it didn't work, you would have to get eyeglasses to correct the astigmatism with a +2.5 progressive add to give you the near.

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And yes, if your brain can make sense of the different images then you do get blurry vision. The sphere in my near eye is at -1.0 D which is a little short of giving good near vision. But, I have -0.75 D astigmatism, of which about 50% is additive to the sphere to give me about -1.4 D overall. I have pretty good near vision. But probably because my astigmatism is not symmetrical (with opposite pie pieces being exactly the same), and is skewed to one side of my eye, I see a drop shadow effect on text. I can kind of ignore it, but I'm sure I would see better and quicker without it"