Simulating Vivity (and other non-monofocal) IOL experience using visionsimulations
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There's a website called visionsimulations (first hit on google), which seems to have a nice collection of various types of sight impairment tests, night time dysphotopsias etc.
If there are folks with a "good eye" or a monofocal that can realistically even evaluate their vision using this tool, it would be really nice go get their perception if this simulator is actually good.
There's some details i haven't been able to get a great coherent answer for when trying to evaluate things like the contrast loss of the Vivity lens and experiences correcting your vision with glasses.
Contrast sensitivity in real life:
One of the tests is a loss-of-contrast simulator with some sliders for different shades and strengths of gray.
If someone has the vivity in one of their eyes and the other one is using a mono-focal or something else, where it can be evaluated satisfactorily, is the vision simulator for contrast sensitivity in any configuration (values on the sliders) accurate representation of what you see with the vivity lens?
Exotic lens correction with glasses:
Because of the exotic structure of the non-monofocal lens like vivity, have you had challenges getting a sharp image out of glasses at distances where they are needed, especially considering the power-magnification of the central part of the lens. Has there been issues where glasses are unable to give you sharp vision or is that something you don't even have to worry about and everything is clear once corrected with glasses.
Hopefully this reaches some people that can pitch in.
0 likes, 1 reply
RonAKA Spoo
Edited
First off, I am skeptical of these computer based simulations. Why? Well if a typical computer setup with a monitor has your eyes 14-18" away from the screen, this is not at all like distance vision. So I don't see how you could simulate any kind of distance vision with a computer simulator.
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In any case I did some comparisons between my two eyes which have monofocals but at different defocus positions. If you refer to figure 4 in the Vivity Package Insert PDF, my lenses are represented by the SN60WF curve. In my right eye the lens will match the curve as it is my distance eye. The lens in my left eye is the identical shape but is offset to peak at about the -1.5 position (2 feet). As you can see the MTF measure of contrast sensitivity peaks in my right eye at the 0.0 or infinity distance position at 0.45. But when I view it at 2 feet which is a little back from my normal seating position, the MTF is essentially zero or what should be a very bad contrast sensitivity. In my other eye which is offset to peak at the -1.5 D defocus position my contrast sensitivity should be at the peak value of 0.45, or excellent.
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With this in mind I looked at the first image in the contrast sensitivity examples at the website you suggested. It is the one with the table and 4 chairs and some varying shades of gray and black squares on the wall behind the table. With either eye I have to slide the strength of gray slider right down to zero to get a reasonable contrast. But, even there if I was doing a digital darkroom adjustment of the image I would cut the exposure down a bit more to make it look right.
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But getting to your point, with the slider down to zero I see little difference between the two images where the MTF of the lens is at the peak of 0.45 compared to where the peak should be essentially zero. Yes if I switch back and forth between the eyes, my near eye which is at the theoretical peak contrast point is very slightly better in contrast. If they were prints I would have to have them side by side to see a difference.
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My thoughts on this are that I suspect the MTF or contrast sensitivity value is a minor player in the overall vision. Visual acuity measured by LogMAR is much more critical. My close eye at this distance is at a LogMAR of -0.05 or potentially 20/15 except that I have some astigmatism that probably makes it fall short of that. And the distance eye is at a LogMAR of -0.35 which is probably closer to 20/45 or so. And from a visual acuity point of view there is some easily seen difference between the two eyes even though I start to see reasonably well at 18" in my distance eye, which is probably better than the curve indicates. Conclusion? Visual acuity counts, but contrast sensitivity not so much.
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On eyeglass correction I have no personal experience other than with my monofocals I can get excellent correction. In my under corrected near eye I can get a corrected 20/15 vision, and 20/20+ in the distance eye. I think the issue with Vivity and Eyhance lenses is that they tend to have a flatter peak in visual acuity and that can make choosing the correct eyeglass correction a little harder through the "Which is better, A or B?" process. And the other part is that with progressives the standard progression in power may not match that needed with the extra intermediate that these EDOF lenses provide. But that is a guess on my part. I would also guess it is harder still with the MF IOLs like the PanOptix and Synergy.
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Hope that helps some,