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Author Topic: Astigmatism cylinder  (Read 6030 times)


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Astigmatism cylinder
« Reply #1 on: July 18, 2011, 09:16:05 AM »
Q: My O.D. changed my glasses (non-dominant eye) from Sph 0 Cyl -1.50 to Sph +.5 Cyl -2.00. All other numbers are the same. I am nearsighted in both eyes. I was told that the Cyl cancelled out the Sph. for no change. Is that true? I am having some discomfort.
A: The spherical equivalent of +0.50 with a -2.00 cyl is a -0.50 (not the same). Sometimes when a person is use to a spherical correction and it is changed to the full cylinder correction, they cannot tolerate the change,even though it is correct. In these cases, the doctor will often "cut the cylinder". This means the cylinder value is reduced and the sphere value is adjusted to keep the spherical equivalent the same. If you cannot adjust to the new glasses, your doctor will want to know and possibly recheck you.