How much is our field of view:

(a) with one eye open?

(b) with both eyes open?

The near point of a long-sighted person is 50 cm from the eye.

(a) Can she see dearly an object at:

(i) a distance of 20 cm ? (ii) at infinity ?

(b) To read a book held at a distance of 25 cm, will she need converging or diverging spectacle lenses?

A person can read a book dearly 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

Which of the following have a wider field of view?

(a) Animals having two eyes on the opposite sides of their head.

(b) Animals having two eyes at the front of their head.

Out of animals of prey and predators, which have their eyes:

(i) at the front of their head?

(iii) on the opposite sides of their head?