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प्रश्न
A man can read the number of a distant but clearly but he finds difficulty in reading a book.
What type of spectacle lens should he use to correct the defect?
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उत्तर
To correct his defect of vision, he should use convex lenses in his spectacles.
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संबंधित प्रश्न
The kind of lens required to correct Myopia
Your friend can read a book perfectly well but cannot read the writing on blackboard unless she sits on the front row in class.
Is she short-sighted or long-sighted?
Explain with the help of labelled ray diagram, the defect of vision called myopia and how it is corrected by a lens.
An eye has a far point of 2 m. What type of lens in spectacles would be needed to increase the far point to infinity? Also calculate the power of lens required. Is this eye long-sighted or short-sighted?
Differentiate between members of the following pair with reference to what is asked in the bracket.
Rods and cones (sensitivity).
What is meant by optical illusion? Give one example.
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.
List two causes of presbyopia. Draw labelled diagram of a lens used for the correction of this defect of vision.
Choose the correct answer :
Presbyopia is a disease of _____________
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.
Have a look at the posture of this woman who is reading a book and answer the questions which follow:
What are the two conditions shown in sections A and B of the eye as applicable to her?
Explain the Term: Hypermetropia
Give Technical Term:
The path which responsible for protecting the eye from sweat.
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.
In Myopia the human eye _______.
Observe the figure whether it is correct or not and explain the phenomenon.
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.
