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प्रश्न
A person cannot read newspaper placed nearer than 50 cm from his eyes. Name the defect of vision he is suffering from. Draw a ray diagram to illustrate this defect. List its two possible causes. Draw a ray diagram to show how this defect may be corrected using a lens of appropriate focal length.
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उत्तर
The person is suffering from Hypermetropia i.e. far-sightedness.
Hypermetropia is caused due to:
(i) The focal length of the eye lens is too long
(ii) Decrease in the length of the eyeball
This defect can be corrected using convex lens of appropriate focal length.
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संबंधित प्रश्न
Explain two possible reasons of myopia. How can it be corrected? Explain with a suitable diagram.
What is the scientific name of
short-sightedness
Name the defect of vision in which the eye-lens loses its power of accommodation due to old age.
Name any two defects of vision which can be corrected by using spectacles.
A student sitting in the last row of the class-room is not able to read clearly the writing on the blackboard.
How can this defect by corrected?
What is long-sightedness? State the two causes of long-sightedness (or hypermetropia). With the help of ray diagrams, show:
(i) the eye-defect long-sightedness.
(ii) correction of long-sightedness by using a lens.
Which part of the eye is grafted in a needy patient from a donated eye?
Write whether the following is true or false:
A convex lens is used for correcting myopia.
Explain the Term: Hypermetropia
What type of lens is used to correct Hypermetropia?
