Will correct iol diopter in each eye, set for infinity, require reading glassed of same prescription for each eye?

[Coney19]

In theory, would cataract surgery that placed  monofocal iol's of the correct diopter for focus at infinity in each eye, provide the same depth of field (that is, the same loss of focus at close distance) in each eye, and therefore require the same prescription in the left and right lenses of the reading glasses? Just from my experience with the optics of photographic lens, it would seem to be the case, assuming each eye was sending images of the same size to the brain.  I have just had cataract surgery for both eyes, and find that one eye is focusing considerably closer than the other. There is just enough overlap of field of focus with reading glasses to make reading possible without too much trouble.Thanks.

[John C Hagan III, MD, FACS, FAAO]

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[JodieJ]

I think it would be easy to determine what is contributing to your refractive error.  Just get an eye exam.

BTW, those complex formulas used to determine your IOL power aren't foolproof.  Generally, there is a margin-of-error of +/-.5D.  No cataract surgeon can guarantee that both of your eyes will be plano post-surgery.  Sometimes having one eye a little nearsighted is advantageous because it improves near/intermediate vision.

[Coney19]

Thank you for your comments. And you're right about my eyesight. I was near-sighted in both eyes all my life, but especially so in my left eye. I was one of those young people with glasses that tipped over to one side because of the much larger weight of one eyeglass lens.

For many years while wearing contact lens, and before the cataract problems began, I was always able to use reading glasses with lens for each eye of the same strength. Currently, after the cataract surgery on both eyes I have 20/20 vision in my right eye, but as I mentioned in my first posting, the left eye begins being in focus at a considerably closer distance than does my right. My question is about what this means in terms of whether the left eye with its new iol now in place for almost two months is properly focused on infinity.

I can't definitively answer the question due to the astigmatism in that eye. I am to see the surgeon in three weeks and wanted to obtain information from members of this board in order to be able to discuss the matter and what the best solution to correct it is.

It would appear that a surgical procedure of smoothing the cornea is required to eliminate the astigmatism of my left eye, but before that I would like to know if the monofocal iol has the correct diopter to provide focus at infinity (as does the right eye) and that the smoothing procedure would resolve the issue, or would I find myself without astigmatism but somewhat nearsighted because the left eye iol's diopter is incorrect.

[JodieJ]

Your eyes probably weren't identical before surgery.  Possibly the calculations used to select the right IOL power for distance vision worked better for one eye than the other.  If you got prescription reading glasses (or better yet, progressive glasses), I'd expect that you'd have excellent vision at all distances.