Avatar universal

refraction for eye with a cataract, complicated by regular astigmatism

I have regular astigmatism in my left eye that has causes the double vision effect, which for a number of years I have corrected with contact lenses and glasses (along with my nearsightedness).  But I was diagnosed with mild cataracts in both eyes in 2017, which has become more progressed in my left eye to the point of needing surgery.

I hope I can word the following so that it makes sense.  I believe the cataract may be contributing to my astigmatism, so during an eye test, I don't know how much I should try to focus on eliminating the double image.

When I take an eye test now, there is no way to get rid of the double vision entirely.  When I take the test, the object of getting rid of the double vision is at odds with the object of making the test sharper.     For if I make it my goal to merge the double image of the letters on the eye chart into one, saying "better" to the lens that moves the double images closer, as I continue, then the letters can be moved closer and closer together, but at the price of sharpness of the letters. I wind up with the letters almost in sync as one, but not really readable.

If on the other hand, if I ignore the doubling and just say "better" as to whether the lens is making the letters sharper, I will end up with sharp text, but with two overlapping images remaining a problem.  

Let me just put it this way as a way of restating the above, to make sure I am understood.  If my life were on the line and I was told I had to read a page of text correctly, I would choose the latter option and rely on a lens that made the text discernible, but with an annoying double image.  Because if I try to merge the double letters with the lens options provided into the text, the end result is fuzzy unreadable text, much of which I  wouldn't be able to make out even if I tried.

So with the above being true, my question is :   How much the results of my eye exam are used in choosing my IOL?

Here are the history of my refractions:

Refraction Dec 2015
OD: Sph -6.25 Cyl +1.50 Axis  055  VA - Dist: 20/20-1   ADD: 2.00
OS: Sph -6.25 Cyl +2.00 Axis  095  VA - Dist: 20/20-1   ADD: 2.00

Refraction May 2017
OD: Sph -6.00 Cyl +1.50 Axis  056  VA - Dist: 20/20   ADD: 2.00
OS: Sph -6.50 Cyl +2.25 Axis  095  VA - Dist: 20/25-1   ADD: 2.00
OD: Sph -5.00 Cyl +1.50 Axis  048  VA - Dist: 20/20  
OS: Sph -5.50 Cyl +2.25 Axis  081  VA - Dist: 20/25-1  
    (this was for a prescription that combined computer distance prescription)

Refraction Aug 2018  (in this exam i focused on merging the lettering in left eye and ended up still very blurry)
OD: Sph -5.25 Cyl +1.50 Axis  050  VA - Dist: 20/20   ADD: 2.25
OS: Sph -7.50 Cyl +2.75 Axis  081  VA - Dist: 20/50-1   ADD: 2.25

Refraction  Jan 2019  (in this exam I just went for whatever made the lettering sharper and readable with my left eye, ignoring double vision)
OD: Sph -5.50 Cyl +1.50 Axis  048  VA - Dist: 20/20-1   ADD: 2.25
OS: Sph -7.00 Cyl +2.50 Axis  090  VA - Dist: 20/60-   ADD: 2.25

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Avatar universal
Thanks, that does ease my mind.  
Helpful - 0
177275 tn?1511755244
Regular astigmatism is not a problem; irregular astigmatism is.  Put your mind at ease. the IOL formula has nothing to do with what your glasses RX is or what you pick when doing a glasses test ( Refraction)  It depends on measurements of your cornea, length of eye and other internal measurements, a A constant peculiar to each IOL and a empirically determined modification of the formula used based on the surgeons previous surgery with that IOL.
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177275 tn?1511755244
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