Study the diagram given below and answer the questions that follow : (i) Name the defect of vision…
Study the diagram given below and answer the questions that follow :
(i) Name the defect of vision represented in the diagram. Give reason for your answer.
(ii) List two causes of this defect.
(iii) With the help of a diagram show how this defect of vision is corrected.
Solution
(i) Hypermetropia or Far-sightedness.
Reason – Image is formed behind the retina. / Near point for the person is farther away from the normal near point (25 cm)
(ii) Focal length of the eye lens is too long.
The eyeball has become too small.
(iii) [ray diagram of a hypermetropic eye lens]
N = Near point of a hypermetropic eye
N'= Near point of a normal eye
