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By opthalmology there are two types of spectacle lenses.SPHERICAL CYLINDERICAL. Charecteristics of these pl

According to opthalmology there are two types of spectacle lenses.SPHERICAL and CYLINDERICAL. let me know the charecteristiuc sof thse lenses. When we placed the spericl lens under a source of light its obtained image is CIRCLE without change in AXIS i.e 180. When we placed the Cylinderical lens under a source of light its obtained image is ELLIPSE with chang ein axis. How to get a stable POWER of THE CYLINDERICAL GLASS wit change in axis?

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  • 1 decade ago
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    Spherical lenses look like a portion of a sphere, cylindrical lenses look like a portion or cut from the side of a cylinder.

    To get an image that is as good and "without" what you call change in axis, you have to use two of these cylindrical each oriented for one axis; for example, one horizontal, one vertical. That's how astigmatism is corrected. I think you should word your questions right!

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