Science
A person needs a lens of power –5.5 dioptres for correcting his distant vision. For correcting his near vision he needs a lens of power +1.5 dioptre. What is the focal length of the lens required for correcting (i) distant vision, and (ii) near vision?
Human Eye
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Answer
Power is reciprocal of focal length.
(i) Focal length of the lens required for correcting distant vision = = -0.181 m = -18.1 cm
(ii) Focal length of the lens required for correcting near vision = = 0.667m = 66.7cm
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