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प्रश्न
Given below is a diagrammatic representation of a defect of the human eye:
(i) Identify the defect.
(ii) Mention two reasons for the above defect.
(iii) State how the defect can be rectified.
(iv) Name the part of the eye responsible for maintaining the shape of the eyeball.
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उत्तर
(i) Hypermetropia (Far-sightedness) because the image is behind the retina.
(ii) Reasons for hypermetropia are:
1. Shortening of the eyeball from front to back.
2. The lens becomes too flat.
(iii) It can be rectified by using convex lenses of appropriate power (focal length).
(iv) Sclerotic (or sclera).
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संबंधित प्रश्न
Name any two defects of vision which can be corrected by using spectacles.
What are the two most common defects of vision (or defects of eye)? How are they corrected?
A person can read a book clearly only if he holds it at an arm's length from him. Name the defect of vision:
if the person is an old man
Given below is a diagram depicting a defect of the human eye. Study the same and answer the question that follow:
Name the defect shown in the diagram.
Draw a ray diagram to show how Hypermetropia is defect can be corrected using a lens.
State the main functions of the following:
Tears
List two causes of presbyopia. Draw labelled diagram of a lens used for the correction of this defect of vision.
Study the following diagram carefully and then answer the questions that follow. The diagram is depicting a defect of the human eye :
(i) Identify the defect shown in the diagram.
(ii) Give two possible reasons for the above defect.
With respect to human eye explain:
(i) How is the image formed on the retina?
(ii) How is the amount of light entering the eye-controlled?
(iii) What type of lens is used for the correction of ‘Long sight’ defect?
(iv) With the help of a ray, diagram show the defect of the eye and then its correction after the use of a lens.
Have a look at the posture of this girl who is reading a book and answer the questions which follow:
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- Name the problem she is facing.
- What are the two conditions shown in sections A and B of the eye as applicable to her.
- What kind of reading glasses does she need?
 |
 |
| A | B |
