Astigmatism Questions

Trying to understand astigmatism a little better.

From my understanding the horizontal blur with letters is related to astigmatism?
Which can also be caused from “correcting” astigmatism that is not actually there?

Asking because with my current lens “correction” that does have cylinder values, I have notice that if I am looking at a sentence while wearing my lenses and I move my head up or down, the result is that at only a certain degree point there is vertical blurring. HOWEVER, when I am not wearing lenses the vertical blur is constant.

So does real astigmatism visually change what you’re looking at constantly or only on the degree at which the astigmatism occurs?

I know my current “correction” is not correct and I am trying to figure out if what I am noticing is lens induced astigmatism or general myopic blur.


Did you try to measure your astigmatism using the astigmatism dial?

I regularly measure my cyl and sph cm values using the dial.
I find that astigmatism is very dynamic. It fluctuates.
Also, in my experience, eye strain makes it much more noticable (directional blur, double images are more noticable)

I suggest you read everything you can about astigmatism, until you understand it fully. Then you can make educated decisions as per which lenses to order.


I have recently since I printed a better scaled dial.
My main issue with measuring for astigmatism is that I have permanent blind spots in both eyes (left eye it is just left of the optic nerve and the right is in the lower right of my vision. So regardless I have issues with double vision, specifically in my left eye. Trying to differentiate between whether it is astigmatic or due to the blind spots presents a challenge. I know in one of Jake’s videos though he talks about telling if you have astigmatism by figuring out if your double vision resolves itself when you focus or move further or closer to the object. If I give my vision a few seconds the double image does resolve itself. But as you said it is also dependent on the day and amount of eye strain. I honestly don’t feel like I have astigmatism or if I do it is very low. My most recent correction was reading -1.75 and -2.25 but after reviewing the charts that I could get from optometrists it shows no astigmatism, a gap in records and the suddenly I am up to -2.25! I am wondering if the measurement, based off of the auto-refractor were miscalculated because it doesn’t take into account the blind spots and damaged photo-receptors that I have, thereby giving a false reading for the cylinder.

But in regards to my question, I only notice and directional blur/stretched letters when a) wearing my current correction (when I have no glasses I don’t see directional blur, just double vision) b) when the object I am looking at seems to fall of the axis of the alleged astigmatism

I fail to find a clear answer of this elsewhere: what differentiates double vision from astigmatic blur and how can I tell them apart?

afaik both create the same misalignment effect…

EDIT: This was solved elsewhere, nvm