As an additional note, it is better to look at the equivalent spherical correction to judge the difference between the 2 eyes. This is because while all the optometrists and some of the opthamologists in USA would have written your eye prescription the way you have it, most of the opthamologists in USA would have written it as:
OD -1.25 + 0.50x106
OS -3.00 + 1.25x67,
from which the spherical correction difference would have come out as 1.75D.
Brilliant! Such interesting information. Thank you so much for sharing. This helps me. I am not sure how you arrived at the -1.25 number and the -3.00 number but this does explain why I am struggling and why giving my left eye distance support helps. Can you share how you arrived at these numbers?
Essentially, when one has regular astigmatism, the prescription is not the same at all angles on the cornea: it needs one value along one axis and a different value at 90 deg to it.
For example, for distance vision, your right eye needs -1.25 at 16 deg (and 196 deg) and -0.75 at 106 deg (and 286 deg)
The way some doctors write it (as your doctor wrote), they essentially say that the prescription is -0.75 at all angles and there is an additional negative correction of -0.50 at 16 deg (and 196 deg). The overall prescription is then written as:
-0.75 -0.50x016
In this convention, the second value (corresponding to astigmatism) is always written as a negative number.
In the alternate convention, used by the majority of opthamologists in USA, the value corresponding to astigmatism is always written as a positive value, To do that, for your right eye, they will say that the prescription is -1.25 at all angles and there is an additional positive correction of +0.50 at 106 deg (and 286 deg). The overall prescription is then written as:
-1.25+0.50x106.
Thus both ways of writing the prescription will end up providing you the same values for your right eye; i.e. -1.25 at 16 deg (and 196 deg) and -0.75 at 106 deg (and 286 deg)
If you use a similar procedure for the left eye, you will be able to arrive at the -3.00 number.
Thank you so much! Very informative and helpful!
One other question before I leave you in peace - I noticed yesterday that images shift when I cover one eye and look out of the other. They seem "normal" with my left eye when I cover my right eye. When I cover my left eye, the images shift up and slightly tilt up. Have any of you heard of this. Perhaps this is part of my problem. I put a 1.00 contact in my left eye to bring both eyes to where they are basically seeing at the same distance (-0.75). No improvement in the image shift. I still see the same shift when I cover my left eye. Just curious to what degree this is normal and if you have ever heard of this happening before. Perhaps this is part of my adjustment problem?
The vertical misallignment of the images seen by the 2 eyes could definitely be a reason for your adjustment problem. The left eye is probably your dominant eye so that the image does not shift when you cover the right eye, but the misallignment could be due to an issue with either (or both eyes). This can best be addressed by the surgeon by checking if the new lenses are exactly as they should be in the eyes. For exaple, an unintended tilt in one of the lenses could produce such an effect. If so, he/she should be able to re-position it.
Thank you. The shift actually happens in my right dominant eye. Weird! I will have this checked out!
Is there a test for vertical alignment. My surgeons office says to come back in a month. That my eyes are still healing. Is there a particular test an optometrist can run to test for vertical alignment. Seems like nobody wants to listen to the patient. I would love to know the name of that test.
1. There is probably a special test, but I am not aware of it. They probably just depend on the feedback from a patient.
2. Just curious. I assume that the glasses you wear in addition to the 0.5D contact lens in the left eye have the astigmatism correction also. If so, does the image shift when you wear the combination of the contact lens and the glasses. If the image does not shift with the combination, then the difference in the astigmatism between the eyes can be a part of the explanation.
No astigmatism correction yet. That could explain some of the shifting. That will be something to try when I see the optometrist on Wed. Thank you!
Hope that the astigmatism correction with glasses takes care of the problem. Otherwise, may need to check if the new lenses in the eye are in the desired position.
Got some glasses at full prescription with full astigmatism correction. They make me feel like my eyes are torquing and pulling and they make my eyes and eye area very tense and stressed and actually worsen my symptoms of vertigo. Very hard to concentrate, read, play piano, drive. Image differences are still present. I spent a good deal of time on the phone with a specialist in Binocular Vision Dysfunction - specifically Vertical Heterophoria. I am going to see them the first week in May. Hopefully this can be solved with a simple pair of glasses with prism. Last appointment with surgeon is next week and will have him check the placement of the implants but fully expect to hear that all looks good. Any advice/experience with BVD and Vertical Heterophoria?
Very sorry to learn about the serious vision issues which you are having. It is good that you are seeing the surgeon and another specialist in Binocular Vision Dysfunction soon to sort this out.
Am just curious. Did you actually get glasses at full prescription with full astigmatism correction. As I mentioned before, any time the prescription in the glasses for the 2 eyes is more than 1 diopter different, the chances of having binocular vision problem go up because of different size images. So, you may be having binocular vision issues due to combination of reasons rather than just one reason. If you can bring the glasses prescription closer by using a contact lens in the left eye for part of the correction to at least avoid the "different image size" issue (as you had tried earlier), it may be easier to sort out the other reason for the vision issue.
Adding to my suggestion above, if you don't want to try a contact lens in addition to glasses, you may want to try a prescription of -0.75-1.25x127 (instead of -1.75-1.25x127) in your left eye without changing the prescription of the right eye (-0.75 -0.50x016) without wearing any contact lens in your left eye. You will be using slight monovision but that may work out for the best in your case.
Thank you. I appreciate this suggestion so much. I did get glasses at full correction with full astigatism correction in both eyes. The astigmatism in my left eye actually improved to -.75 though. My optometrist thinks I am totally whacko and tells me to just live with these glasses until my last appointment with my surgeon and then they will write me a prescription when I get the go ahead from the surgeon. I have little hope left with them. So - getting another set of glasses is impossible right now and I am just living with a contact in my left eye with the .5/.5 glasses. The BVD specialist. however, will do an exam and then work with me on the right prescription whether that be glasses or a glasses/contact combo and then they will add small amounts prism to align the images in my eyes. I spent a good 1.5 hours with them on the phone and am encouraged that they will be able to help me with find a solution. It gives me hope. The thought of wearing a contact AND prism glasses for the rest of my life just doesn't sound appealing but I think I will go ahead and talk to them before I opt for Lasik surgery. Uggghhhh - I don't like the thought of more eye surgery. Thank you for your kind reply. Always so helpful.
I am glad that you can at least operate with the contact lens (-1.0?) in the left eye together with the -0.5 / -0.5 (?) prescription lenses. Am not sure why most of the optometrists or opthamologists don't pay any attention to the impact on the binocular vision due to the big difference in the prescription for the 2 eyes.
It is good that you have an appointment with the BVD specialist. That should be a big help.
Just as a trial, you may want to also try using the -0.5/-0.5 prescription glasses without the contact lens (-1.0?) in the left eye. It is possible that this will work also. If you are comfortable with that, you may find that your near vision is better without a significant impact on your distance vision, compared with the contact lens & glasses combination (you will essentially be using monovision which many people, including me, adapt quickly to)
Sorry that I forgot that you had already tried essentially what I proposed above but it did not work out for you.
I just got back from a Binocular Vision Dysfunction specialist in Texas. Such a wonderful place and caring doctor. Diagnosis - Vertical Heterophoria with symptoms precipitated by the cataract surgery. Fascinating! Looks like it will be glasses with a small amount of prism in the left lens to start - probably with some tweaking over time as my eyes settle in. She said the with prescription implants as strong as mine, any misalignment, however miniscule, can cause these problems especially if I had any asymptomatic alignment issues before the surgery which I may well have had. The trial glasses felt so good. I won't get my new glasses for a couple of weeks ( Boo Hoo) but am so encouraged! Thank you for all of your help and I will keep you posted.
I am so glad that you were able to find a Binocular Vision Dysfunction specialist, who could diagnose your vision issue and come up with a solution, which will work for you.