How effective are multi-focal contacts if the manufacturer is recommending a monovision like fit?


For stronger add powers, they recommend that different multi-focal patterns for distance and near go in each eye, and that you’re aiming for 20/20 at distance in one eye, and near in the other.

Does this actually help the patient use monovision more effectively? Is there any real benefit to the other eye having peripheral focus to pair with the other eye? If the secondary power only has 20/40 visual acuity, is it doing anything? Or is this a big scam to charge more for monovision fit contacts?

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I don’t know the first thing about any contacts so no opinion there.

However, I spoke with a friend a couple weeks back that had cataract surgery and chose monovision lens implants. He’s 80 or 81, and reads multiple books a week without glasses. We talked vision for a good while. He said he has no eye strain while reading and could look up and have good distance vision instantly. He has glasses that corrects his near lens to far that he only uses occasionally for driving under low light. He wasn’t aware of which eye was corrected for distance until he occluded each to check. He said he could detect a slight improvement in his distance vision when he used binocular vision.

It was a great conversation. I am amazed at what the visual cortex can do with varying types of information. May not be of any help to you, but it seemed worth sharing.

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Yeah, not everyone can adapt to mono-vision, but it works really well for a lot of people. It even occurs naturally sometimes.

A box of Biofinity Multifocal lenses is $77.97. A box of regular Biofinity lenses is $44.99. On top of that, the lens range available is smaller in multifocal. I’m just saying there are cheaper ways to get monovision if that’s all the Multifocal fitting process does for you.

https://coopervision.com/practitioner/our-products/biofinity-family/biofinity-multifocal

This advanced design contains multiple zones of vision correction in both lenses, allowing for clear vision up close, at middle distances, and far away. Our streamlined fitting approach and unique technology means you can fit even more patients with ease and flexibility, while giving them excellent vision.

But yet the package insert does not set nearly so high a goal on a per-eye basis.

I don’t understand multifocal contacts. Above my head. Anyway, I refuse to put anything in my eye willingly!

I don’t have great choices about it. I can wear my prior pair of glasses forever, accept whatever the optometrist is willing to give me, go to another country to get my glasses, or wear contacts.

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The concept of multifocal is kind of like bifocals, but you can’t look through a specific part, your visual cortex has to work it out that it wants to use peripheral vision for some distances.

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… I’m looking at this going like
optometrist who is ok with my normalized glasses did not recommend contact lenses for me
different focal planes in each eye===my binocular vision would go thru a fit

can’t speak for others but just not for me

Yeah, monovision isn’t for everybody.

Huh, stumbled on that while I was searching up on monovision tolerance:

Monovision performed better than a center-near aspheric simultaneous vision multifocal contact lens of the same material for distance and near VA only. The multifocal option provides better stereoacuity and near range of clear vision, with little differences in CSF, so a better balance of real-world visual function may be achieved due to minimal binocular disruption.

Oh, now I’ve really fallen down a rabbit hole. There’s some study where patients who were not monovision tolerant had a surgery to change Q-factor. I’ve not found a good definition, but it sure sounds like q-factor is astigmatism. Is cylindrical astigmatism actually a defense against presbyopia?

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Interesting. Sometimes I feel the universe is trying to tell me something; whenever I start thinking of astigmatism in terms of “my eyes are distorted”, I find another rabbit hole humbling with complexity saying that maybe astigmatism is actually natural and healthy.

Could this be part of why EM participants do not tend to develop strong presbyopia, if any? If part of what we consider “aberration” is actually functional, it makes sense that not “correcting” for it anymore may have it work for its intended purpose.

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I’ve always understood some cases of astigmatism arise from constantly moving the eye in a specific direction all of the time especially for people who play musical instruments

In some countries it is normal recommendation above 50.
I know people who applied this and are now happy. And also others who tried but could never get their brain process the images.
It’s definitely a brain game.

As for the contact lenses
Not many people can tolerate standard contact lenses long term (usually because of overusing or incorrect fitting).
The multifocal contact lenses rotate back to intended position (close up bottom - distance top) after each blink => constant irritation.
I know a couple of people who tried the multifocal contacts but went back to multifocal glasses after a few months as the irritation was too much.

Very commonly done here for single vision contacts or cataract surgery.

I just don’t see paying double for multifocal contacts if they don’t provide much more benefit than monovision fit single vision contacts.

I found a better description of q value, it’s a symmetrical distortion, not cylindrical astigmatism. A sphere has a q factor of 0. A parabolic surface with no spherical aberration would be -0.5. The average human eye is -0.26, lens is -0.25 in young people, so combined value is close to the ideal -0.5. As we age, the lens drifts towards 0.

In the study they were aiming for Q factor of -0.8.

https://crstodayeurope.com/articles/2012-jul/the-fundamentals-of-spherical-aberration/

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