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
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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