Refraction after catarat surgery in eye targeting intermediate

Can you recommend a good conversion table for diopters to Snellen measurement?

I understand that there is no perfect conversion and individual results vary. But the numbers I've found so far on the internet are all over the map. I'd be very interested in any reasonable, semi-scientific population averages.

I'm seeing estimates of about 20/60 to 20/100 for -1.5 D. Some of these are from optometrists' websites and some reference not-very-current research (though I suppose it's the sort of thing that does not change much over time).

Yes, there are different estimates. To some degree even standard monofocals differ, and then there are enhanced monofocals, and EDOF lenses which all will have a slightly different defocus curve. The problem still is that individual results do vary a lot. I use a generic curve that I have some reasonable faith in. Looking at it, makes me realize I had a bit of a brain fart when I quoted 20/30 or 20/40 in the post above, and it is now too old to edit. You are correct that it will be more like 20/100 for distance vision when you are at -1.5 D. I was thinking about close reading vision at 1 foot or so, the opposite end of the defocus curve. Click on Figure 1 at this location. A -1.0 would put you at about 20/40, which would be very marginal for legal driving vision.

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Semantic Scholar Optimal amount of anisometropia for pseudophakic monovision. Ken Hayashi, Motoaki Yoshida, +1 author H. Hayashi Published 1 May 2011 Medicine Journal of refractive surgery

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Sorry for the confusion...

Thanks for the clarification!

Thanks Ron, Just to confirm I understand, would you say if I hit the target of -1.5D in my intermediate eye, then I would be moderately near sighted but still see well enough to read without eyeglasses? I would likely have 20/100 vision at a distance?

Yes, that is correct. I am typing and reading these posts with no glasses and a -1.60 D eye. I tried closing my distance eye and checking to see what distance vision was like with only the -1.60 D eye when going on a walk in the neighbourhood today. 20/100 sounds terrible but I could easily read most house numbers provided they were at least 4" tall. So, it is not like you are blind, which is kind of like I was when I used to need -4.0 D correction lenses.

I had a brief refraction today and was told the vision in my operated eye is 20/100. It was much better when the technician used the piece of plastic with tiny holes (if you know what I mean!) The vision in my unoperated eye was 20/125.

When outside, unexpectedly, I have the impression of distance vision. This is not the case when inside however.

Unfortunately the 20/100 number is expected but not that helpful in determining where you ended up. The measurement you really need to know is the diopter refraction. But, at one week it is unlikely to be very accurate, in any case.

Is the diopter refraction the number I would see under sphere in my eye glasses prescription?

Yes, likely. There are normally three numbers listed and usually in this order:

Sphere, Cylinder, Axis

Sphere and Cylinder are in diopters, while Axis is in degrees...

Wow, I'm constantly getting confused... Now I understand. I declined a refraction yesterday because I'd like to have that done in 4-6 weeks.

If they did that test where you look through an instrument and see a hot air balloon or house out in the distance, they will have done an autorefraction. It is not as accurate as a snellen test with a phoroptor, but should give you some indication of where you are at. If they did that test you may be able to give the clinic a call to see if they will give you the results.