A long-sighted person has a minimum distance of distinct vision of 50 cm. He wants to reduce it to 25 cm. He should use a
Options

Question

A long-sighted person has a minimum distance of distinct vision of 50 cm. He wants to reduce it to 25 cm. He should use a

G1 Physics · Accepted Answer

Derived solution: Step 1: Use the thin-lens relation for the correcting lens and the eye defect: a convex lens corrects hypermetropia, a concave lens corrects myopia, and a cylindrical lens corrects astigmatism. Step 2: Substitute the values given in the question and apply the geometry/sign convention shown. Step 3: On simplification the result is Convex lens of focal length 50 cm. Therefore the correct option is C.