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प्रश्न
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.
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उत्तर
(i) Myopia.
(ii) 1. Vitreous humor
2. Fovea
3. Optic nerve
(iii) 1. Lengthening of the eyeball from front to back.
2. Lens is too curved.
(iv) Correction of Myopia:
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संबंधित प्रश्न
Name the defect of vision which makes the eye-lens cloudy resulting in blurred vision.
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.
The near-point of a person suffering from hypermetropia is at 50 cm from his eye. What is the nature and power of the lens needed to correct this defect? (Assume that the near-point of the normal eye is 25 cm).
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.
The defect of vision which cannot be corrected by using spectacles is:
(a) myopia
(b) presbyopia
(c) cataract
(d) hypermetropia
Name the following:
The eye defect caused due to shortening of the eye ball from front to back.
List two causes of presbyopia. Draw labelled diagram of a lens used for the correction of this defect of vision.
In what two whys is a yellow spot different from the blind spot?
Draw a neat labeled diagram to show how hypermetropia can be rectified.
A person needs a lens of power –4.5 D for correction of her vision.
- What kind of defect in vision is she suffering from?
- What is the focal length of the corrective lens?
- What is the nature of the corrective lens?
