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प्रश्न
A student has difficulty reading the blackboard while sitting in the last row. What could be the defect the child is suffering from? How can it be corrected?
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उत्तर
A student has difficulty in reading the blackboard while sitting in the last row. It shows that he is unable to see distant objects clearly. He is suffering from myopia. This defect can be corrected by using a concave lens.
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संबंधित प्रश्न
What is myopia?
What is the far point and near point of the human eye with normal vision?
The far point of a myopic person is 80 cm in front of the eye. What is the nature and power of the lens required to correct the problem?
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.
Name one defect of vision (or eye) which cannot be corrected by any type of spectacle lenses.
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?
A student sitting in the last row of the class-room is not able to read clearly the writing on the blackboard.
Name the type of defect he is suffering from.
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?
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?
Though a woman can see the distant object clearly, she cannot see the nearby objects clearly. She is suffering from the defect of vision called:
(a) long-sight
(b) short-sight
(c) hind-sight
(d) mid-sight
A young man has to hold a book at arm's length to be able to read it clearly. The defect of vision is:
(a) astigmatism
(b) myopia
(c) presbyopia
(d) hypermetropia
You do not enjoy watching a movie from a very short distance from the screen in a cinema hall. Why?
State the main functions of the following:
Tears
Have a look at the posture of this woman who is reading a book and answer the questions which follow:
What kind of looking glasses she needs?
In what two whys is a yellow spot different from the blind spot?
What type of lens is used to correct Astigmatism?
Write scientific reason.
Nearsightedness, this defect can be corrected by using spectacles with concave lens.
What are the causes of ‘Myopia’?
Correlate the given sequence:
Hypermetropia : Convex lens : ______ : Concave lens
