(a) What are the values of (i) near point and (ii) far point of vision of a normal adult person?

(b) A student has difficulty in reading the blackboard while sitting in the last row. What could be his defect of vision? Draw a ray diagram to illustrate this defect of vision.

(a) (i) The near point of vision of a normal adult person is = 25 cm from the eye

(ii)The far point of vision of a normal adult person is infinity because farthest point from the eye is the point at which an object can be seen clearly.

(b) A student has difficulty in reading the blackboard while sitting in the last row. What could be his defect of vision, this defect of vision is known as Myopia. Myopia is eye defect in which a person can see nearby objects clearly but is unable to see the distant objects.

Myopia is the defect of the eye vision due to which a person can see the near objects clearly, nut he cannot see the far objects clearly.

The ray diagram to illustrate the defect and the correction diagram are as follows: