A person's near point is 50 cm and his far point is 3 m. Power of the lenses he requires for (i)  reading and (ii)  for seeing distant stars are

For correcting the near point, required focal length f=50×25(50−25)=50cm  So power P=10050=+2D For correcting the far point, required focal length  f=−( defected far point )=−3m ∴P=−13D=−0.33D