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प्रश्न
Distinguish between the following pair of words:
Myopia and hypermetropia
उत्तर
| Myopia | hypermetropia |
| (i) The image of distant object is produced in the front and not on the retina . | (i) The image is produced beyond the retina as the light rays are unable to converge on the retina. |
| (ii) It results from abnormally long eyeball . | (ii) It results from abnormally short eyeball. |
| (iii) The defect can be produced by high convexity of the lens . | (iii) The defect can be produced by low convexity of the lens . |
| (iv) It can be corrected by the use of spectacles having concave lens . | (iv) It can be corrected by the use of spectacles having convex lens . |
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संबंधित प्रश्न
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List three common refractive defects of vision. Suggest the way of correcting these defects.
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?
What is the other name for
myopia
What is the other name for
hypermetropia
What is the scientific name of
short-sightedness
A man can read the number of a distant but clearly but he finds difficulty in reading a book.
From which defect of the eye is he suffering?
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?
Given below is a diagram depicting a defect of the human eye. Study the same and answer the question that follow:
Name the defect shown in the diagram.
State one role of ciliary muscles in the human eye.
What is Hypermetropia (far sightedness)?
State the main functions of the following:
Tears
The diagram alongside represents a section of a mammalian eye.
(i) Label the parts 1 to 5 of the diagram.
(ii) State the function of the parts labelled 4 and 5.
(iii) With the help of a diagram show the short sightedness.
Name an old age eye defect. Why is it caused?
Differentiate between:
Short-sightedness and Long-sightedness.
Given below is a diagrammatic representation of a defect of the human eye:
(i) Identify the defect.
(ii) Mention two reasons for the above defect.
(iii) State how the defect can be rectified.
(iv) Name the part of the eye responsible for maintaining the shape of the eyeball.
Assertion: Myopia is the defect of vision in which a person cannot see distant objects clearly.
Reason: This due to eye-ball being too short.
A person is unable to see clearly a poster fixed on a distant wall. He however sees it clearly when standing at a distance of about 2 m from the wall.
- Draw ray diagram to show the formation of image by his eye lens when he is far away from the wall.
- List two possible reasons of this defect of vision.
- Draw ray diagram to show the correction of this defect using appropriate lens.
Name the following:
Two kinds of accomodations.
