Question

Given below is a diagram depicting a defect of the human eye. Study the same and then answer the questions that follow:

(i) Name the defect shown in the diagram.

(ii) Give two possible reasons for this defect of the eye in human beings.

(iii) Name the parts labelled 1 to 4.

(iv) Name the type of lens used to correct this eye defect.

(v) Draw a labelled diagram to show how the above mentioned defect is rectified using the lens named above.

Answer 1

(i) The defect shown in the diagram is Myopia

(ii) Two possible reasons for this defect of the eye in human beings are :

1. excessive curvature of eye lens
2. elongation of eyeball

4. Concave lens

3. The parts of the eye diagram labeled 1 to 4 are:

1. vitreous humour
2. retina
3. lens
4. pupil

5. In myopia defect the image is formed in front of the retina, so to rectify it we use a concave lens which forms the image on the retina and the defect is rectified