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प्रश्न
A student is unable to see clearly the words written on the black board placed at a distance of approximately 3 m from him. Name the defect of vision the boy is suffering from. State the possible causes of this defect and explain the method of correcting it.
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उत्तर
The boy is suffering from nearsightedness i.e. Myopia. The possible causes for this defect are Elongation of the eyeball.
Excessive curvature of the eye lens
This defect can be corrected by placing a concave lens in front of the eye.
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संबंधित प्रश्न
Which defect of vision can be rectified:
by using a convex lens?
Differentiate between myopia and hypermetropia. What type of spectacles should be worn by a person having the defects of myopia as well as hypermetropia? How does it help?
A person can read a book clearly only if he holds it at an arm's length from him. Name the defect of vision:
if the person is an old man
Name the following:
The eye defect caused due to shortening of the eye ball from front to back.
By closing the eyes and gently pressing them by your palms, you may see some specks of brilliant light. How do you get this sensation while there is no light entering your eyes?
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.
Differentiate between:
Short-sightedness and Long-sightedness.
Explain the Term: Presbyopia
In Myopia the human eye _______.
Differentiate the eye defects: Myopia and Hypermetropia
