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प्रश्न
Rewrite the following table so as to match second and third column with first column.
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Column I
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Column II
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Column III
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(i) Myopia
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Old age problem
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Bifocal lens
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(ii) Presbyopia
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Nearsightedness
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Concave lens.
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उत्तर
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Column I
|
Column II
|
Column III
|
|
(i) Myopia
|
Nearsightedness
|
Concave lens.
|
|
(ii) Presbyopia
|
Old age problem
|
Bifocal lens
|
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संबंधित प्रश्न
Given below is a diagram showing a defect of human eye. Study it and answer the following questions.
(i) Name the defect shown in the figure.
(ii) Give reason for this defect of eye in human being.
(iii) Name the type of lens used to correct the eye defect.
What is myopia?
A student suffering from myopia is not able to see distinctly the objects placed beyond 5 m. List two possible reasons due to which this defect of vision may have arisen. With the help of ray diagrams, explain
(i) why the student is unable to see distinctly the objects placed beyond 5 m from his eyes.
(ii) the type of the corrective lens used to restore proper vision and how this defect is corrected by the use of this lens.
(b) If, in this case, the numerical value of the focal length of the corrective lens is 5 m, find the power of the lens as per the new Cartesian sign convention
Explain two possible reasons of myopia. How can it be corrected? Explain with a suitable diagram.
the biological/technical terms for the lens of eye losing flexibility resulting in a kind of long-sightedness in middle aged people.
What is the other name for
myopia
Name the body part with which the terms myopia and hypermetropia are connected.
What is the far point of a person suffering from myopia (or short-sightedness)?
A man can read the number of a distant but clearly but he finds difficulty in reading a book.
From which defect of the eye is he suffering?
Explain with the help of labelled ray diagram, the defect of vision called myopia and how it is corrected by a lens.
A person suffering from the eye-defect myopia (short-sightedness) can see clearly only up to a distance of 2 metres. What is the nature and power of lens required to rectify this defect?
A person cannot see the distant objects clearly (though he can see the nearby objects clearly). He is suffering from the defect of vision called:
(a) cataract
(b) hypermetropia
(c) myopia
(d) presbyopia
What is meant by optical illusion? Give one example.
Enumerate the common defects of vision, their causes and the possible methods of correcting them.
A student cannot see a chart hanging on a wall placed at a distance of 3 m from him. Name the defect of vision he is suffering from. How can it be corrected? Draw ray diagrams for the (i) defect of vision and also (ii) for its correction.
What is Hypermetropia (far sightedness)?
A student has difficulty reading the blackboard while sitting in the last row. What could be the defect the child is suffering from? How can it be corrected?
When do we consider a student sitting in the class to be myopic? List two causes of this defect. Explain using a ray diagram how this defect of eye can be corrected.
Distinguish between the following pair of words:
Myopia and hypermetropia
Given alongside is a diagram depicting a defect of the human eye. Study the same and then answer the questions that follow:
(i) Identify the defect.
(ii) Name the parts labelled 1, 2 and 3.
(iii) Give labelled two possible reasons for this eye defect.
(iv) Draw a labelled diagram to show how the above mentioned defect is rectified.
Given below is a diagram depicting a defect of the human eye? Study the same and answer the question that follow :
Name the type of lens used to correct this eye defect.
Give Reason:
Why do we see clearly in the central region of the retina?
Explain the Term: Presbyopia
Give Technical Term:
The type of lens used to correct myopia is
What type of lens is used to correct Hypermetropia?
The diagram given below represents the cross-section of the human eye:
(i) Name the parts labeled 1—12.
(ii) What is the function of the part marked ‘10’?
(iii) What would happen if part ‘5’ is damaged or cut?
Mention, if the following statement is True or False
Hypermetropia is a defect of the eye caused due to the eyeball elongation
Choose the Odd One Out:
In Myopia the human eye _______.
A person cannot see distinctly objects kept beyond 2 m. This defect can be corrected by using a lens of power:
Assertion: Myopia is the defect of vision in which a person cannot see distant objects clearly.
Reason: This due to eye-ball being too short.
Myopia may arise due to ____________.
Which of the following statement is correct?
When do we consider a person to be myopic or hypermetropic? Explain using diagrams how the defects associated with myopic and hypermetropic eye can be corrected?
Correlate the given sequence:
Hypermetropia : Convex lens : ______ : Concave lens
A person is unable to see clearly a poster fixed on a distant wall. He however sees it clearly when standing at a distance of about 2 m from the wall.
- Draw ray diagram to show the formation of image by his eye lens when he is far away from the wall.
- List two possible reasons of this defect of vision.
- Draw ray diagram to show the correction of this defect using appropriate lens.
Complete the following table by observing the given figures:
| Figure → |  |
 |
| Points ↓ | ||
| (a) Name of the defect | ______ | ______ |
| (b) Position of the image | ______ | ______ |
| (c) Lens used to correct the defect | ______ | ______ |
Name the following:
Two kinds of accomodations.
