Question

A short-sighted person cannot see clearly beyond 2m calculate power of lens required to correct this.

This question is of class10th
chapter:-Human eye!!

Need solution with explanation!!!

Answer 1

here, u = - infinity, v = - 2m (or -200cm)

1/f = 1/v - 1/u

1/f = -1/2 + 1/infinity

therefore, f=-2m

P = 1/f = -1/2 = - 0.5 D

hence power of lens req is - 0.5 D

Answer 2

f = - 2m
so, P = 1/-2
P=-0.5D