Lens choice for second cataract surgery

Thanks Ron. If I go with -1.50D lenses in both eyes, would you say that I can get single vision glasses for distance and not need progressives? I haven't worn single vision glasses since I was in the 9th grade. It sounds less expensive and perhaps the lenses would be thinner? Would that be true also if I go with lenses set for mini-monovision?

My cataract surgeon said he thinks I can tolerate plano but I'm thinking now I would prefer to have both eyes the same or just a minimal offset. In terms of seeing more clearly just inside the house, do you think it would be worth it to go with the minimal offset (less than 1 diopter)? I can't image how far I would see with my RE set to -1.0D for instance.

Thanks so much for all your help. My questions seem endless even to me.

If you go with -1.5 D in both eyes you certainly can go with single vision distance glasses. For sure you will need glasses of some kind for distances beyond 8 feet or so. You will have to take these single vision glasses off and on all day though to see closer than 3 feet or further than 8 feet. I would not tolerate that situation if it were me.

.

There will be no significant difference in the thickness of the lens. I have progressive that correct my mini-monovision (but don't wear them), and they are the thinnest glasses I have ever worn.

.

I think you are overly concerned about the offset between the eyes. If you end up at -1.50 in your close eye, and you will not know that until you have had a detailed refraction, and at -0.25 D in the distance eye, the differential will only be 1.25 D. That is not much, and I agree with your surgeon that you are very likely to get along well with that differential.

Yes. The original plan was -2.00 D in my "near" eye and -1.00 D in my "distance" eye, all on a spherical equivalent basis.

.

The -2.00 D target was to maximize the likelihood of achieving very good near vision without risking too much of a compromise of intermediate vision. If it and a -1.00 D "distance" eye target had been achieved, Eyhance defocus curves suggested a very high likelihood of very good near and intermediate vision together with a reasonable likelihood of legal driving vision (mean monocular distance VA of 20/32). As luck would have it, I have the near/intermediate vision I wanted with -1.50 D in my "near" eye and better than the distance vision I'd hoped for in my "distance" eye.

Sounds great RebDovid. So you ended up with -1.5 for near and -1.0 for distance? If yes, that sounds like what I would like to target as well. Will you be wearing either single vision glasses or progressives?

On a spherical equivalent basis, my September refraction showed -1.50 for near and -0.50 D for distance.

.

I got single vision glasses, also in a monovision set-up. I can read even the small print on medicine bottles without assistance and have 20/25 distance vision, so I didn't feel the need for either readers or progressives. In fact, I might have gone without buying glasses altogether except that (1) I wanted a pair just in case I sometimes felt the need when driving in poor visibility conditions and unfamiliar areas and (2) except when engaged in outdoor activities that might put prescription glasses at risk, I thought they might serve as general sunglasses by getting Transitions Xtractive Polarized lenses.

.

Again on a spherical equivalent basis, the glasses bring my vision to 0.0 D / -0.50 D. I decided to put them in the ultra-light Lindberg Corona frame in which I'd had my pre-surgery progressive lenses. Altogether they're so light that they do work as general sunglasses and they sharpen my vision just enough so that I wear them more than I thought I would driving at night. (But I've yet to encounter a situation where I've felt I really needed them to drive safely.) I also find my self putting them on to watch television programs and movies with subtitles. (My wife and I sit a little more than 10' from a 55" screen.)

.

The bonus is that, at least for short intervals (I haven't tried much longer), I also can read my smartphone without having to remove my glasses.

Thanks RebDovid! What is the meaning of 'on a spherical equivalent basis'?

Spherical Equivalent (SE) is a conversion of a prescription which has both sphere and cylinder to an estimated sphere only. Unfortunately most IOL implants end up with some residual astigmatism (cylinder). Using SE to some degree estimates that impact on your vision. For example take this prescription. Sphere: -2.0 D, Cylinder -1.0 D. You convert it to SE by adding half of the cylinder to the Sphere. So the SE in this case is -2.5 D. Some only consider Sphere when discussing their targets with the surgeon and then are surprised when they end up with Cylinder and a SE of more than they expected, even when a toric lens is used.

.

SE is also used when selecting a contact lens and don't want to use a toric lens. In the example above you would use a contact of -2.50 D Sphere instead of one with -2.0 D Sphere and -1.0 D Cylinder.

Thanks Ron!

Thanks David!

I would agree, but one really needs to see the IOL Calculation sheet to see what the actual choices are. Unfortunately some surgeons like to keep that a "big secret".

I didn't realize that. Not sure why they'd intentionally withhold your own medical information. Also I should clarify that I'd choose first minus as long as it's not too close to 0. Like if the first minus prediction is -0.06 for example I think -0.39 (next step down) would be a better choice.

Courts in the US and Canada have ruled that medical information belongs to the patient, not the doctor, and they cannot refuse to give it to you legally. But they can be difficult about it. While this IOL Calculation data sheet only requires a click of the mouse to produce, they can (according to the court decisions) make you request the information in writing, and they can charge you the cost to produce it. Cooperative surgeons will just click the mouse and hand it to you.

.

Targeting the first minus and targeting -0.25 D is essentially the same thing. When you look at the IOL Calculation sheet it will show a range of about 4-5 power choices. There is always a decision to be made as of course these choice are not going to be in even 0.25 D steps. That is why it is nice to see the calculation sheet and be involved in the decision. I recall that the IOLMaster sheet can show more than one formula results so a decision also has to be made as to which formula or combinations of formulas to trust. If two good formulas like the Hill RBF 3.0 and Barrett Universal II formulas closely agree, that gives one confidence.

.

I also think the practicality of it is that few patients unless they are prepared for what they see will understand it. And, the surgeon wants to minimize the time they spend with each patient, so they withhold it so they don't have to explain it.

Right but in my case the first minus in one of my eyes is technically -0.04. Practically though I'd say its -0.38 because the -0.04 is essentially 0 and way to close to plano for comfort. Now if first minus was -0.2 I'd be ok with that but if it was -0.12 or something I'd have to think about that and may go the next step up in power.

Based on my memory only, my first eye which was being done for distance was almost exactly the same. I recall the surgeon saying that this power would give you perfect plano vision, but I do not recommend it due to the risk of going positive. He said that nobody ever thanks him for leaving them positive (far sighted). He suggested the next step which I recall was estimated to end up at -0.37 D SE. My vision actually turned out to be 0.0 D Sphere and -0.50 D Cylinder for an SE of -0.25 D. Surgeon was right. I would have ended up slightly far sighted if I had gone with the power estimated to be plano. Vision was 20/20+.

"And, the surgeon wants to minimize the time they spend with each patient."

That is sadly the case with many cataract surgeons. Some, however, will take time with you, but they are under pressure to get patients in and out.