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प्रश्न
What changes take place in the shape of eye-lens:
when the eye is focused on a distant object?
उत्तर
When the eye is focussed on a distant object, the eye lens gets stretched and becomes thinner. This is because, when the eye is focused on a distant object, the ciliary muscles are completely relaxed. The relaxed ciliary muscles pull the suspensory ligaments tightly. As these ligaments become tight, they pull the eye lens, because of which the eye lens becomes thinner (or less convex).
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संबंधित प्रश्न
How does the eye regulate the amount of light that falls on the retina?
Where is the image formed in a human eye?
What do the ciliary muscles do when you are focusing on a nearby object?
What change is made in the eye to enable it to focus on objects situated at different distances? Illustrate your answer with the help of diagrams.
Name the respective organs in which the following are located and mention the main function of each:
(i) Iris
(ii) Semicircular canals
Choose the Odd One Out:
Draw the struture of human eye and label its parts.
A tiny mirror M is fixed on a piece of cardboard placed on a table. The cardboard is illuminated by light from a bulb. The position of eye with respect to position of bulb is shown in the figure as A, B, C and D. In which position mirror will be visible?
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 |
 |
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| (A) | (B) | (C) | (D) |
Match the following:
| Column - I | Column - II | ||
| 1 | Retina | a | pathway 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 |
The figure given below refers to the vertical section of the eye of a mammal. Study the figure carefully and answer the following questions.
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- Label the guidelines shown as 1 to 10.
- Write one important role of parts shown as 3 and 7.
- Write one structural difference between the parts shown as 9 and 10.
- Mention one functional difference between the parts shown as 6 and 8.
