Question

Study the diagram given below and answer the question that it follows: 

(a) Which defect of vision is represented in this case? Give reason for your answer. 

(b) What could be the two causes of this defect? 

(c) With the help of a diagram show how this defect can be corrected by the use of a suitable lens.

Answer 1

(a) The defect is hypermetropia, as the image of near point is formed beyond retina. 

(b) Two causes of the defect are: 

(i) Size of eye ball decreases. 

(ii) Focal length of the lens increases. 

(c) This defect can be corrected by using a convex lens of suitable focal length.