$A$ person cannot read a book at distances less than $50\, cm$. Name the defect of vision he is suffering from. How can it be corrected? Draw ray diagrams to show the image formation
$(i)$ by defective eye and
$(ii)$ after using corrective lens.

(N/A) The defect of vision is Hypermetropia,also known as long-sightedness.
In this condition,the person can see distant objects clearly but cannot see nearby objects distinctly because the image of a nearby object is formed behind the retina.
It can be corrected by using a convex lens of suitable power,which converges the light rays before they enter the eye,allowing the image to be formed exactly on the retina.