Calculate maximum power of accommodation of a person having normal vision

(i) Calculate maximum power of accommodation of a person having normal vision.
(ii) A person needs to use glasses for reading newspaper. Identify the defect in her vision and the type of lens she would need to correct ii
(iii) Sometimes when we enter into a dark room from bright sunlight we are unable to see objects clearly. Why?

(i) D = 25 cm, Now, P = 1// = 100/D= 100/ 25 = 4 D, thus for a person having normal vision, the power of accommodation is about 4 dioptre.
(ii) Long sightedness, a convex lens.
(iii) The pupil regulates and controls the amount of light entering the eye. In bright sunlight, the size of the pupil is small and when we enter a dark room it takes sometime for the pupil to expand in size due to dim light.