Hi-Myope--trying to decide after-surgery focal length
Posted , 4 users are following.
I am having cataract surgery this week. I am a high-myope (-12D / -8D--low astigmatism) but am conflicted on how much minus correction I will want after surgery. I do think I want a short focal length and might be happy w/12”‘-15” or less--maybe way less (if the doctor would agree).
I would love to hear from others who have been very nearsighted for decades and then perhaps finding themselves suddenly having to carry around a magnifying glass.
So, what have you been happy with and/or what might you have done differently?
0 likes, 6 replies
RonAKA pablo325
Edited
I was myopic in both eyes, but not nearly as high as you are. To date I have only had to have one eye done, and I went for plano distance vision in that eye. When it comes time to have the second eye done, I will ask to be left myopic but only by -1.25 D to allow reading at computer distance and iPhone. I currently simulate that arrangement now with a contact in my non IOL eye, and like it a lot. 95% of the time I am eyeglasses free. I do miss the ease of taking my glasses off and seeing really well up close, but instead now I use some +1.25 D readers for the very occasional need. I also have some progressives which I use occasionally. It is nice to have glasses that do not have thick edge lenses. While I only have one eye done, my current progressives are the thinnest and lightest I have ever had, and they are just standard lenses, not high index.
.
Keep in mind that getting an accurate measurement of a high myopic (long) eye is difficult. You may want to find a specialist that does it, as an inaccurate measurement will mean unexpected results, no mater what you choose.
Bookwoman pablo325
Edited
I'm copying and pasting a post I made about a year ago:
I was -8 in both eyes until my surgeries, having been highly myopic most of my life. After reading a lot (including this very helpful forum) and consulting with my ophthalmologist, we decided that a -2 monofocal lens in each eye was the way to go. I spend roughly 80% of my day reading or on the computer, and the thought of not being able to see close up when not wearing glasses was horrifying. Close vision is what my brain has always been used to, and I wanted to keep it that way.
I was not interested in multifocal lenses, given the issues that some people have had with them, and I don't mind wearing glasses at all. My doctor suggested mini-monovision as an option, but since I was planning to wear glasses anyway, I didn't want to risk any discrepancy between the two eyes that would be too great for my brain to handle. (As you probably know, while there are targets for what your vision will be after surgery, the outcomes can vary.)
I wound up with my dominant eye at -2 and my other eye at -2.5. The fact that my unaided vision is now so much better than it has been at any time since my childhood is still a source of delight and wonder to me. I can, without glasses, read and work on the computer (a desktop with a large monitor), see clearly when I look in the mirror (yikes!), walk around my house and see reasonably well, etc. For watching TV and driving I wear glasses with progressive lenses, which allow me to see really well at every distance. The upshot is that I'm absolutely thrilled with my vision.
Good luck with whatever you decide!
rwbil pablo325
Edited
*“I want a short focal length and might be happy w/12”‘-15” or less”
I was myopic for most of my life before cataract surgery, but not as much as you. All I can point out is the tradeoffs.
You mention 12-15 close vision desired. But are you looking for 20/20 at that distance? If you use a non diffractive IOL and shoot for 20/20 at 12” you vision going out in distance will get bad pretty quickly. I highly suggest you get out a defocus curve for the IOL you are thinking about and see what the average results would be.
Is your goal to just have close and intermittent vision and then wear glasses for distance? I cannot relate to that as I need good distance.
If you want to get 20/20 distance and 20/20 15” close vision, I think you would need a diffractive IOL and the tradeoffs that come with it. To accomplish this via monovision, would most likely require full monovision, which comes with its own problems.
If your eyesight is still good enough do a test run with contracts to try different myopic settings to test how your distance will be and see if you like it.
So my advice start with this:
1)Decide what vision you need at 12”-15”; is 20/32 good enough?,
2)Decide on few IOLs you are thinking about,
3)Pull out the defocus curve for that IOL and plot the 12”-15” mark and see what minus diopter setting is required to achieve those results,
4)See what effect that decision will have on your distance vision.
pablo325 rwbil
Edited
Hi rwbil, I am going monofocal all the way and do not want distance correction for more than one reason, the most important one being I have prism 3.00 base out. This means I am essentially "cross-eyed" at more than ~30". I am leaning toward 12" focal length (closest reading distance for most people). This means the IOL target needs to aim for about -3.25 based on this cool calculator (metric): https://www.translatorscafe.com/unit-converter/en-US/diopter-optical-power-to-focal-length/).
Not sure what you mean by 20/20 at 12”. I think you are trying to say best focus at 12" but there may be another use for 20/xx I am not aware of.
RonAKA pablo325
Posted
It all comes down to what you want to see with no glasses on, and that is kind of a personal preference. I have found that I really dislike wearing reading glasses because when I look up across the room at other people or the TV everything being out of focus makes me nauseous. But, reading glasses can be taken off, or you can get those half lens glasses that lets you look over top of them.
.
I see your point about having prism and that you will need glasses for distance. I think if I was in your situation I would go for full distance correction with a monofocal and plan on wearing progressive glasses full time. Full distance will minimize the correction you need in your glasses while going for a close focus of -3.25 will of course require eyeglasses with a -3.25 correction - medium thickness. Normal practice with progressive is to use a +2.5 add in the bottom of the lens. The latest design progressives like those sold at Costco are pretty good.
rwbil pablo325
Posted
"This means the IOL target needs to aim for about -3.25 based "
This is why I say all I can do is present some of the tradeoffs as everyone is different. I personally cannot relate as this setting will lead to great close up vision with vision quickly get worse as you look out.
To me most of life happens at distance or intermittent and cannot imagine having to reach for glasses to watch TV or go out for a walk or a hike and on and on.
But everyone is different and you have to decide what is best for your lifestyle.
If there were no diffractive IOLs or even the new "Enhanced" Monofocal IOLs. I would set the monofocal for distance and maybe do a little bit of monovision to gain a bit more intermittent and then wear readers for the relatively small amount of time I would need them. But that is me!