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What is Cylindrical glass is used for: and explain in detail?
Ans. (d) AstigmatismRef: A.K. Khurana 6th ed. 142-43, Harrison's 19th ed./ 195* Astigmatism is a type of refractive error which arises due to irregular curvature of cornea.* Correction of astigmatism is done by using cylindrical lens.