Question

A person can read a book clearly only if he holds it at an arm's length from him. Name the defect of vision:
(a) if the person is an old man
(b) if the person is a young man

Answer 1

(a) If the person is an old man, then the defect of vision is presbyopia. It usually occurs in old age when a person cannot see nearby objects clearly because of the loss of the eye's power of accommodation.

(b) If the person is a young man, the defect of vision is hypermetropia. Hypermetropia occurs either because the eye lens has low converging power or because the eyeball is too short. This makes the near vision defective.