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प्रश्न
Which defect of vision can be rectified:
by using a concave lens?
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उत्तर
Myopia can be rectified by using concave lenses.
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संबंधित प्रश्न
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?
Name the defect of vision in a person:
whose near point is more than 25 on away.
What is the scientific name of
short-sightedness
Your friend can read a book perfectly well but cannot read the writing on blackboard unless she sits on the front row in class.
What type of lenses-converging or diverging-would an optician prescribe for her?
The defect of vision in which the eye-lens of a person gets progressively cloudy resulting in blurred vision is called:
(a) myopia
(b) presbyopia
(c) colourblindness
(d) cataract
Explain the terms ‘adaptation’ and ‘accommodation’ with reference to the eye.
Enumerate the common defects of vision, their causes and the possible methods of correcting them.
State one role of ciliary muscles in the human eye.
An old man cannot see objects closer than 1 m from the eye clearly. Name the defect of vision he is suffering from. How can it be corrected? Draw ray diagram for the (i) defect of vision and also (ii) for its correction.
Choose the odd one out from the following terms and name the category to which the others belong.
Endolymph, Tympanic membrane, Semi-circular canal, Blind spot
Write whether the following is true or false:
A convex lens is used for correcting myopia.
Choose the correct answer :
Presbyopia is a disease of _____________
Given below is a diagram depicting a defect of the human eye? Study the same and answer the question that follow :
Name the type of lens used to correct this eye defect.
A person is unable to see objects distinctly placed within 50 cm from his eyes.
(a) Name the defect of vision the person is suffering from and list its two possible causes.
(b) Draw a ray diagram to show the defect in the above case.
(c) Mention the type of lens used by him for the correction of the defect and calculate its power. Assume that the near point for the normal eye is 25 cm.
(d) Draw a labeled diagram for the correction of the defect in the above case.
Draw a neat labeled diagram to show how hypermetropia can be rectified.
What type of lens is used to correct Astigmatism?
What type of lens is used to correct Hypermetropia?
Differentiate the eye defects: Myopia and Hypermetropia
Match the following:
| Column - I | Column - II |
| 1. Retina | a. Path way of light |
| 2. Pupil | b. Far point comes closer |
| 3. Ciliary muscles | c. near point moves away |
| 4. Myopia | d. Screen of the eye |
| 5. Hypermetropia | e. Power of accommodation |
Have a look at the posture of this girl who is reading a book and answer the questions which follow:
 |
- Name the problem she is facing.
- What are the two conditions shown in sections A and B of the eye as applicable to her.
- What kind of reading glasses does she need?
 |
 |
| A | B |
