Question

The near point of a person suffering from hypermetropia is 75cm. Calculate the focal length and power of lens required to enable him to read the newspaper which is kept at 25cm from the eye.

Answer 1

1/f=1/v-1/u

1/f=1/25-1/75

=-1/50

f=37.03m

P=1/f=2.7D

Answer 2

if the focal length is 25cm then the power is 4dioptre