For a person near point of vision is 100 cm. Then the power of lens he must wear so as to have normal vision, should be:

For normal vision, u = −25 cm
Given : v = −100 cm
Using lens formula
1/v − 1/u = 1/f
1/−100 − 1/−25 = 1/f
⇒ f = +100/3 cm = +1/3 m
Power of the lens used
P = 1/f
where f is in meter
∴ P = +3 D