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प्रश्न
State reasons for Myopia. With the help of ray diagrams, show the:
- image formation by a myopic eye, and
- correction of myopia using an appropriate lens.
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उत्तर
Myopia is a visual impairment in which a person can see all around objects clearly, but finds it difficult to comfortably focus on a single object. This eye is referred to as the myopia eye.
Myopia can be caused by:
- increase in curvature of the lens.
- increase in the length of the eye ball.
(a) A myopic eye's far point is close to that infinite distance. In front of the retina, it creates the separate object image depicted in the figure.
(b) Concave lens has an ability to diverge incoming rays, it is used to correct this defect of vision. The image is allowed to form at the retina by using a concave lens of suitable power as shown in the figure.
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संबंधित प्रश्न
Millions of people in the developing countries of the world are suffering from corneal blindness. These persons can be cured by replacing the defective cornea with the cornea of a donated eye. A charitable society of your city has organised a campaign in your neighbourhood in order to create awareness about this fact. If you are asked to participate in this mission, how would you contribute in this noble cause?
(i) State the objective of organising such campaigns.
(ii) List two arguments which you would give to motivate the people to donate their eyes after death.
(iii) List two values which are developed in the persons who actively participate and contribute in such programmes.
A student is unable to see clearly the words written on the blackboard placed at a distance of approximately 4 m from him. Name the defect of vision the boy is suffering from. Explain the method of correcting this defect.
Draw ray diagram for the:-
(i) defect of vision and also
(ii) for its correction.
Name the defect of vision which can be corrected by a converging lens. Show clearly by a ray diagram how the lens corrects the defect.
Which part of the eye is grafted in a needy patient from a donated eye?
Name an old age eye defect. What happens in it?
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:
Draw a labeled diagram to show how the above mentioned defect is rectified using the lens named above.
Give Reason:
Deficiency of vitamin A causes night blindness.
What type of lens is used to correct Hypermetropia?
Choose the Odd One Out:
