$(i)$ Write the range of distance for a person having normal vision.
$(ii)$ $A$ person needs to use glasses for reading a newspaper. Identify the defect in his vision and the type of lens he would need to correct it.
$(iii)$ Sometimes when we enter into a dark room from bright sunlight,we are unable to see objects clearly. Why?

(N/A) $(i)$ The near point for a person with normal vision is $25 \, cm$ and the far point is infinity.
$(ii)$ The defect is Hypermetropia (farsightedness). The person needs a convex lens to correct this defect.
$(iii)$ In bright sunlight,the pupil of the eye is small to allow less light to enter. When we enter a dark room,the pupil takes some time to dilate (expand) to allow more light to enter,which is why we cannot see objects clearly immediately.