Thread: spherical vs cylindrical lens

do they both have same effect on eye? (suppose with same power)

No. Look through a spherical lens, like a magnifying glass, and then look through a cylinder, like a glass of water. Then you will see the difference.

Originally Posted by Harold14370

No. Look through a spherical lens, like a magnifying glass, and then look through a cylinder, like a glass of water. Then you will see the difference.

nice sir......
i went to eye specialist.... he checked my eyesight seperately with these both lenses and asked me "with which lens you see better" and note that both were of same power. why did he asked me this question?

Originally Posted by precious

Originally Posted by Harold14370

No. Look through a spherical lens, like a magnifying glass, and then look through a cylinder, like a glass of water. Then you will see the difference.

nice sir......
i went to eye specialist.... he checked my eyesight seperately with these both lenses and asked me "with which lens you see better" and note that both were of same power. why did he asked me this question?

If you see better with a cylindrical lens than a spherical lens of the same power, that means you have astigmatism. Astigmatism is a condition where your lens or cornea of the eye is not symmetrical, so it needs an asymmetrical lens to correct. However the axis of the cylinder has to be aligned properly for the cylindrical lens to work. If you get a prescription from your optometrist and you have astigmatism, there will be two parts to the prescription, one for the spherical part and one for the cylindrical. The cylindrical part of the prescription will specify the orientation of the axis of the cylinder.

thanx.... for clearing all the stuff