kessie
Lv 4
kessie asked in HealthOptical · 8 months ago

What does the Axis mean in my Optical Prescription?

I had to set aside a new pair of glasses because it felt like my eyes were not positioned correctly. I'm trying to shop for new ones online, but I'm worried about this "Axis" here. I don't know what it's like to have one eye look the other way, but that's what I would imagine it felt like.

Cylinder -0.50 Left & Right, Left 020 and Right 172

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  • 8 months ago
    Favourite answer

    Axis has to do with the orientation of your cylinder. Take a look at the protractor below. Ignore the yellow pins and red lines. I wasn't careful about the image that I picked. Notice that 172 and 20 are both relatively close to horizontal. In fact one is up a little on the right and the other in the left. What we expect in axis is that the right and left eye will be relatively close to the same orientation. If both are close to vertical or horizontal, one will be rotated a bit one way and the other a bit the other. There is not a problem if your eyes don't follow that rule. Yours do.

    Attachment image
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  • Bernd
    Lv 7
    8 months ago

    This relates to astigmatism, which most people have.

    Sphere = The part of the Rx for nearsightedness or farsightedness 

    Cylinder =  the strength of astigmatism 

    Axis = the angle of astigmatism 

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