Question

Far point of.A myopic eye is 40 cm.What type of lens should he wear so as to see distant objects clearly?Give the focal length and power in its si unit

Answer 1

u =(infinity), v = - 40 cm, f = ?

Using the lens formula, we have

= 1/v-1/u =1/-40- 1/infinity = 1/-40 = 40 cm= -0.4 m

Hence, power of lens to be used is

P= 1/f = 1/-0.4 = -2.5D