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Question
What is myopia?
Solution
Myopia or near-sightedness is the defect of vision in which a human eye can see nearby objects distinctly but is unable to see distant objects clearly. In this case, the image of a distant object is formed in front of the retina instead of on the retina.
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RELATED QUESTIONS
In a Std. X class out of 40 students 10 students use spectacles, 2 students have positive power and 8 students have negative power of lenses in their spectacles.
Answer the following questions:
(1) What does the negative power indicate?
(2) What does the positive power indicate?
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(5) Give two possible reasons for the above defect.
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What is the other name of old age hypermetropia?
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A student sitting in the last row of the class-room is not able to read clearly the writing on the blackboard.
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Draw a ray diagram to show how Hypermetropia is defect can be corrected using a lens.
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Given below is a diagram depicting a defect of the human eye? Study the same and answer the question that follow:
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(a) Name the defect of vision the person is suffering from and list its two possible causes.
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(d) Draw a labeled diagram for the correction of the defect in the above case.
Give Reason:
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Give Reason:
Deficiency of vitamin A causes night blindness.
Give Reason:
When you enter into a dark room from bright because of sunlight, you can not see things for a few seconds.
Explain the Term: Presbyopia
Explain the Term: Cataract
What type of lens is used to correct Astigmatism?
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(iii) State how the defect can be rectified.
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