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प्रश्न
Differentiate between:
Short-sightedness and Long-sightedness.
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उत्तर
| Short-Sightedness | Long-Sightedness |
| (i) The inability of the eye lens to focus images of distant objects on the retina; so the images fall in front of the retina. | The inability of the eye lens to focus near object images on the retina; so the images fall beyond the retina. |
| (ii) It is corrected by using glasses of a concave lens. | It is corrected by using glasses of a convex lenses. |
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संबंधित प्रश्न
Name the defect of vision in a person:
whose far point is less than infinity
Name the defect of vision which makes the eye-lens cloudy resulting in blurred vision.
Name any two defects of vision which can be corrected by using spectacles.
What is short-sightedness? State the two causes of short-sightedness (or myopia). With the help of ray diagrams, show:
(i) the eye-defect short-sightedness.
(ii) correction of short-sightedness by using a lens.
An eye has a near point distance of 0.75 m. What sort of lens in spectacles would be needed to reduce the near point distance to 0.25 m? Also calculate the power of lens required. Is this eye long-sighted or short-sighted?
The defect of vision which cannot be corrected by using spectacles is:
(a) myopia
(b) presbyopia
(c) cataract
(d) hypermetropia
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
List two causes of presbyopia. Draw labelled diagram of a lens used for the correction of this defect of vision.
The diagram given below represents the cross-section of the human eye:
(i) Name the parts labeled 1—12.
(ii) What is the function of the part marked ‘10’?
(iii) What would happen if part ‘5’ is damaged or cut?
Myopia and hypermetropia can be corrected by:
