Astigmatism on the prescription

Question about astigmatism. Didn’t think I would worry about it until several glasses in, but thought I would check anyway. With my left eye I can check the astigmatism easily, and it agrees with my prescription. BUT with my right eye I can detect no astigmatism, my prescription give the same correction with both eyes. I must be using the tool correctly as it works with the left. Anyone else have this?

The astigmatism on both eyes thing came into optometry pretty recently and I feel it’s bogus because there’s no way it can be in the same direction in both eye. All the more reason to convert it into spherical equivalent and achieve the same vision in all directions.

Hi Bobby,

I am also noticing some issues with improving my centimeter due to astigmatism. I notice that my eyes are dry and or watering sometimes, which also affects my astigmatism. You mentioned converting cylindrical to a spherical equivalent. Is there some sort of guidelines or rules on how to do that? Also have you had or heard of astigmatism from dry or watery eyes? I hope I didn’t ask for too much. Thanks!

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Yes. For every -.50 of CYL, you add -.25 in the SPH, ON TOP of whatever diopter is present.


Thank you for your response. I have a test lens kit, although not very good quality, but I’ll see if I can replace any CYL with SPH. Astigmatism has been the most difficult barrier to my vision improvement.

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Hi! Yes, I have uneven Astigmatism in both eyes. My LE does not have any and RE has -1.00 (I guess). Though I was wearing -0.5 CYL in both eyes before EM. Now, I dropped CYL in both eyes and equated -0.25 SPH in RE alone. These new glasses I am wearing from last 1 week. I see fine with my both eyes, without any headache, dizzyness or any other issues. However, I am not sure about improvements, as my RE constantly has lot of DV to the extent that each line on Snellen is mixed up with bottom one. but LE sees fine. (I see 20/30 with my normalised LE: good, RE: DV)
I would probably continue for some ~8 weeks with these glasses and if there are no improvements, will have to go back to at least -0.5 in RE.
@Bobby did your improvements also took longer at first when you dropped CYL in both eyes?

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Do you know what happens exactly inside the eye when you do that?

I don’t think so, I feel its the same time to improve regardless if you have it or not.

If you put it on your glasses, in whatever direction it set to, that line or axis gets additional clarity.

Thanks! This is giving me confidence again! My Opto said that LE does not have astigmatism but RE is -1.00 CYL. However, I was wearing -0.5 CYL in both. After asking other expert members including you (another thread), I decided to completely drop the CYL, as CYL in only one eye may have caused another issue, who knows. Anyways, I expect getting used to no CYL may take longer time for me, but I will wait till then, before thinking for another reduction.

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I too tried a differential prescription where I dropped my CYL all together, but was worried that I wouldn’t achieve any AF while doing that. I am now considering doing that once again and seeing if the CYL can be replaced with any SPH that way I can focus just on one correction as I keep dropping. This is still something I’m playing around with, but I’ll be sure to share if I learn of anything.

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