Question

the near point of a person suffering from hypermetropia is at 50 cm from his eyes what is the nature and power of the lens needed to correct this defect.

Answer 1

A convex lens of suitable power is required to correct the defect

u=-25 cm
v=-50 cm
therefore,1/-50+1/25=1/f
therefore,1/f=1/50
therefore,f=50cm
therefore,p=1/0.5=100/50=2D
therefore,power=2 dioptre

Answer 2

u=-25 cm

v=-50 cm

p=1/f(meter)

therefore,1/f=1/50

therefore,f=50cm

therefore,p=1/0.5

=100/50=2D

therefore,power=2 D(dioptre)