please help with the math

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  After cataract surgery, a monofocal lens set for distance, My refraction was;  

.-50  and .-50astig.  my l eye was able to read 20/25 on the eye chart.

would someone please tell me what focal point my left eye is at

I do not have a results for the right eye as yet, although the eye was blurry, I could read the 20/40 line.   I have an appt. next week for a refraction.

Note my surgeon did not for for near/far or anything else that he shared with me.   Different options were not discussed.    Thank you. redface 

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  • Posted

    Your equivalent spherical correction is -0.5 -0.25 (half of astigmatism value) for a total of -0.75. Thus, your best focal distance is about 40/0.75 or 53 inches.

    Please note that because of the astigmatism, the best focal point is not the same around the eye. But your astigmatism is relatively small, so you should be able to see the best (very good) at about 53 inches, but probably quite good between 40 and 80 inches. It is obviously fair to good at 20 feet to the eye chart since you can read 20/25.

  • Posted

    many thanks at201 for your reply, i've posted a write up on how my vision has progressed if your interested.    


  • Posted

    my apologies in advance, i have better typing skills but this keyboard is old

    i wanted to post my final results on the cataract surgery for both my eyes so that others have hope.   after reading hundreds of posts across the internet, my opinion is that 1. the skill of the surgeon, 2 the shape of your eyes seem to be the crucial factors. 

    thankfully, all the choices for my eyes were left in my surgeons hands and his choices for me were out of the ballpark.  the graditude that i feel towards that man is beyond words. 

    background  i'm 62yr old female who started wearing glasses at 14 i was near sighted.   my cataracts were first noticed in 2010 but my vision was still correctable to 20/40 although blurry closer distances.

    before surgery best corrected was 20/60, driving at night was impossible the glare test was left 20/100 and right 20/80, and reading was  a hugh strain on my eyes. since quality of life was effected surgury was ok'd by medicaid but ,  i had no choice in facility/nor surgeon.  went into it blind, so to speak. lol.    so, i'm seven weeks out from the left eye and 5 weeks out from the right eye.   and like all the posters have reported, my eyes have gradually improved during this time.

    i was implanted with alcon acry sof iq sn60wf set for distance.  nothing was done to my astigmatism although it did change some.

    worse eye, the left was implanted first,  it was  OS:  -3.50 --.75  x 72 and the right eye was  OD: -3.25 --.75  x 82   and the results two days ago were  

    OD:+0.00 -0.25 x 78 OS:+0.00 -0.50 x 67   and both eyes reading 20/20 seprately and together.    

    so for near, i wear a pr of 1.50 readers for computer reading and for sitting with a book in my lap.  no glasses for long distance  i see to infinity. i see the dashboard and for all household tasks i see great.  sorry ladies, i do need a magnifier for eye makeup.    but for the first time in 50 yrs, i walked out of the eye doctors office with no prescription. just over the counter readers.  nothing short of a miracle to me.  i just wanted some good news for these boards.

    • Posted

      Congratulations on your very good vision achievement! It is great that your vision improved between the earlier and the latest eye tests and that you are now very happy with your cataract surgery results.
    • Posted

      In terms of "wanted some good news for these boards", it is unfortunate that its hard for many people to keep perspective on the reality that most people are happy with the results of their surgeries. Perhaps there should be a pinned post at the top of the forum mentioning that there are over 20 million cataract surgeries a year and most go well and those people never post about it. Those who post are most likely those who had problems. Even if only 1 out of a 1000 people had problems, and 1 out of ten of them bothered posting about it.. that would lead to lots of posts about problems. People get a skewed perspective of how common problems are, since there is no way to tell from just reading online posts what fraction of those who had surgery they are.

      In terms of some good results, I'll add that in   my case I am about 2 years + 1 month postop from getting the Symfony lens in both eyes and just had an eye check this week. I tested 20/15 at distance (they didn't have a line below that to try) and 20/20 at intermediate computer distance (plus a bit off the line below). In the past I consistently tested 20/25 at my best near distance, but this optometrist didn't have a 20/25 line, but I was at least 20/30 at 40 centimeters (rather testing  at my best near distance as the prior tests were) and got at least some letters off the 20/20 line below it.  

      OD: -0.25  -0.25 X 127

      OS: +0.50  (no astigmatism)

      Someday I might consider a laser tweak on the eye that wounded up a bit hyperopic, which is countered by slight what is an accidental tiny amount of myopia in the right eye.


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