Aniseikonia is usually much less of an issue with a contact lenses on the other eye after surgery than it is with glasses since the size difference is smaller. However as you discovered it is still possible since people have different sensitivities. Some people can adapt to larger size differences than others. There is no good explanation for "why this is happening" to you other than bad luck that you are perhaps more sensitive than most.
re: "but with 6D IOL plano was achieved, and then, is 9D IOL on my left eye "
The power for an IOL depends on measurements of the eye like the power of the cornea, they measure the size and shape of your eye and use that to calculate an approximate IOL power. It isn't possible to tell what IOL power someone needs just from their contact lens power. Two people could wear the same contact lens power, but need IOL powers that are a few diopters different from each other. It partly depends on how much of your eye's focusing power is in the cornea, and how much is in the natural lens. You also unfortunately can't tell from the power one eye uses what power the other eye will need because it is possible the measurements of the two eyes aren't the same. Surgeons use formulas that take eye measurements and calculate the approximate IOL power needed to achieve certain focal points for the eye. e..g the formula will say that an IOL power X will likely leave the eye focused at Y diopters (whether 0D for perfect distance, -1.75D for a bit nearer for monovision, etc).
If you didn't have Aniseikonia issues when you wore contact lenses pre-surgery, then after your 2nd surgery you aren't likely to have issues either. Likely whatever monovision worked for you with contacts should likely work for you with IOLs. However you'll note I'm not being definite, unfortunately there is guarantee given you are more sensitive to differences than others, but the doctors should be able to make a more educated guess by running the numbers. The doctors should be able to use your eye measurements to be able to calculate the approximate level of aniseikonia between the eyes that you have now, what you would normally have had before cataract surgery, and what you would have after surgery. Since you are having trouble with the issue, it seems worth asking the doctor to explicitly do the calculations. Whether there is an issue will likely depend on how similar your two eyes are, how much of the focusing power of each eye is in the lens (natural or artificial) and how much is in the cornea.
Your interests have not been served by your surgical team failing to inform you of the problems with your eyes working together (aneisometrophia and aniseikonia) after surgery. It is to be expected. Moreover given the amount of your myopia in your LE one would not expect a contact lens to take care of the problem. Please read this carefully:
http://www.medhelp.org/user_journals/show/1648102/Consider-ALL-the-Options-Before-Your-Cataract-Surgery-Working-Through-Whats-Best-For-You
also since your RE saw 20/20 I wonder why you had cataract surgery at all and further why your LE which has 20/30 was not done first.
If you wrote you LE RX correctly you have 7.5 diopters of astigmatism and you will need to deal with that by toric IOLs or cornea surgery laser or incisional.
Use the search feature and read the many helpful posts by JodieJ on anisekonia from previous discussions.
JCH MD
Here is a paper on the issue for your doctor:
https://www.researchgate.net/publication/51429164_Predicting_refractive_aniseikonia_after_cataract_surgery_in_anisometropia
"Predicting refractive aniseikonia after cataract surgery in anisometropia"
Here is one site with an IOL power calculator that mentions it comes up with aniseikonia if both eye's measurements are used:
http://www.augenklinik.uni-wuerzburg.de/uslab/publ/ios97/shortpap.htm
"Apart from the original input data on the left side, the results for the 2 IOLs selected are given as tables, stating IOL power, resultant refraction and expected aniseikonia."
What is done is done. Still doesn't make sense to do cataract surgery on the eye with the better vision. In any case I think you are stuck with removing the left lens and putting in an IOL for the intolerable aneisokonia/aneisometrophia. With the comments of Software Developer and my article you should be able to make a better choice. Aiming for a post op refraction of 0.00 (plano) RE and -1.75 LE would be mini-monofocal with distance bias. It works very well for many people. To use your eyes together you would need glasses in a no-line multifocal form. You would be able to do many things without glasses. JCH MD
After getting second opinion and reviewing your comment I had my left eye IOL surgery on Feb 18th. It's been just about 4 days since.
My current right eye is plano with 6.5D IOL, advanced from slightly more from my 2 month followup of -0.25. My doctor and I chose my left IOL targeting -1.75 with 9.5D IOL(SEQ Ref -1.79).
I hoped my unbearable aniseikonia would be almost gone after surgery, but I still experience noticeable aniseikonia which is somewhat better to handle than before the surgery though. I have very good near vision with my left eye, I have very clear vision when I use my iphone or anything closer than 1 foot. But things get unclear soon after 1 1/2 foot, and everything is so fuzzy after. My right eye is seeing well from 3 feet and further(20/20).
With my both eyes open, due to the persisting aniseikonia things are not fused well. Mid-range activities like watching TV is not easy. I see very well with my right eye but I see almost nothing well with my left eye. I don't read big letters of 55 inch TV even from 5 feet apart. It affects all my intermediate and distance vision all together.
I am seeing my doctor in 3 week post op. If the difference of diopters is greater than 2 at the time and still have trouble seeing with both eyes after 3 weeks, what could be my best choice to correct or cope with this problem? My corneal thickness is 530 to 540 and I do not feel laser touch-ups is a good option(my doctor also told me the same even before left eye surgery). How about piggybag IOL or even IOL exchange? I know I need to wait at least 3 weeks after surgery to get my left eye diopter accurately but with moderate aniseikonia even after left eye surgery it makes me worried and feel need of informed. Thank you.
Yes, I will try to relax more and hope my brain adjusts to this new vision. After my first 3 week post-op visit I will update you how my visions are settled. I really appreciate your comment.
As the doctor mentions, the issue likely adapting to monovision and not aniseikonia. If possible the hope is to try to not focus on comparing eyes but to just use both and the brain will learn to rely more on the best eye for each distance.
You mention the left eye is targeted at -1.75, the question is whether how closely they hit the mark, and whether perhaps your eye is still not recovered from the surgery in some way and if that is reducing its acuity. The distance a lens is targeted at in centimeters would be (100 / diopters) so the target was a best focus for that eye at 57.1 cm = 22.5 inches, or a bit over the foot and a half where you say thins are clear. The visual acuity going further out with that eye will be reduced, though not too rapidly, so it may be that you were left more myopic than that. These are only average results, so it could be you just have poor luck and are worse than average, but based on the defocus curve in this Alcon document that includes a monofocal IOL:
http://www.alconsurgical.jp/pdfs/RES928.pdf
then if they hit the target then at 1 meter=39.4 inches out that would be +0.75 diopters compared to your eye focus so the data shows that could still be almost 20/20, and at 2 meters = 6.6 feet (+1.25 compared to your eye focus) your eye could be between 20/32 and 20/25, which isn't bad (since to drive you need just 20/40), so your difficulty reading big letters on a large TV from 5 feet makes me suspect you might be a bit more myopic than that.
As the doctor mentions, the issue likely adapting to monovision and not aniseikonia. If possible the hope is to try to not focus on comparing eyes but to just use both and the brain will learn to rely more on the best eye for each distance.
You mention the left eye is targeted at -1.75, the question is whether how closely they hit the mark, and whether perhaps your eye is still not recovered from the surgery in some way and if that is reducing its acuity. The distance a lens is targeted at in centimeters would be (100 / diopters) so the target was a best focus for that eye at 57.1 cm = 22.5 inches, or a bit over the foot and a half where you say thins are clear. The visual acuity going further out with that eye will be reduced, though not too rapidly, so it may be that you were left more myopic than that. These are only average results, so it could be you just have poor luck and are worse than average, but based on the defocus curve in this Alcon document that includes a monofocal IOL:
http://www.alconsurgical.jp/pdfs/RES928.pdf
then if they hit the target then at 1 meter=39.4 inches out that would be +0.75 diopters compared to your eye focus so the data shows that could still be almost 20/20, and at 2 meters = 6.6 feet (+1.25 compared to your eye focus) your eye could be between 20/32 and 20/25, which isn't bad (since to drive you need just 20/40), so your difficulty reading big letters on a large TV from 5 feet makes me suspect you might be a bit more myopic than that.
I am trying not to compare visions of two eyes, and learn how to get acquainted with this new visions. It seems like options for correcting refractive error after cataract surgery for me could bring another whole new outcomes which I would want to avoid at all cost. I hope my left eye shift to a little bit hyperoptic as my right eye did. Thank you so much for your detailed explanation of my condition. I wish I could express my sincere gratitude for Dr. Hagan and you better in words.
It can get tiresome trying different lenses, but since you were 1D off target I would think you might want to try a -1D or even -1.25D or -1.5D lens to see what works best for you.
Perhaps you might get a 2nd opinion from another surgeon re: tweaking the result, since my reading suggests may surgeons do minor tweaks. Last I checked the average cataract patient is in their mid seventies, so perhaps some doctors are too used to dealing with patients with different needs than younger patients. In the case of those of us who have surgery in our early 50s, we have more expectation of living with the results for decades and it seems a shame not to get things tweaked the way we like it if it is possible. My reading suggests in Europe where clear lens exchange (replacing the lens even though the patient doesn't have cataracts) among younger patients is more common than in the US suggests that for clear lens exchange (aka refractive lens exchange) patients there is more of an expectation of getting the final result tweaked to where they want it. That makes sense since their goal was to improve their vision, not merely to treat a cataract, but I suspect it also is partly due to the the average age for clear lens exchange being lower than for cataract surgery so the investment in a tweak is viewed as a paying off over a longer period of good vision.
It sounds like you were off 1D from the target, which seems in the range many surgeons consider laser tweaks. There are other options like lens exchange or piggy back lens, depending on patient, but I think laser is most common for a small tweak due to its low risks, and many suggest PRK rather than lasik. The nationally prominent surgeon I had a followup with saw no problem with the idea of considering a 1D or so tweak for me from +0.5D to -0.5D (or around that, I hadn't bothered with contact lenses to figure out what I'd go for). If the flickering issue I have finally completely resolves (glacially slow change, but improving still) I might consider it since although thats a minor tweak, I'm losing a bit of near so it just seems a waste not to consider it. It seems odd that I never considered lasik during decades of being highly myopic, but it just seems a shame to get so close to having things set perfectly and not finish the job.
I hadn't checked into how the newer laser treatments compare to PRK, like SMILE, since it isn't approved for the hyperopic treatment I'd need, but it is for the myopic treatment you'd need so its something to check on. I also don't know which of the varieties of lasik would be best if that is what they'd use rather than PRK.
Laser adjustments to your vision can be done anytime after the prescription stabilizes, I think often 2 or 3 months are typical timeframes but I hadn't explored what the best figure is since I'm well past that now (15 months).