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प्रश्न
Sometimes you remember a vivid picture of a dream you saw. What is the role of your eyes in this experience?
उत्तर
The brain sees the vivid picture of the dream through the eyes. Our eyes have actually never seen the vivid picture. This is an example of optical illusion. The area of dream is controlled by the cerebrum of the central nervous system. So sometime we can remember the vivid picture seen in the dream.
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संबंधित प्रश्न
The size of the pupil becomes ______ when you see in dim light.
Explain, why a normal eye is not able to see distinctly the objects placed closer than 25 cm, without putting any strain on the eye.
Match the following:
| Column I | Column II |
| (i) Myopia | (a) Converging power of eye lens becomes low |
| (ii) Hypermetropia | (b) Converging power of eye lens remains the same |
| (c) Converging power of eye lens becomes high |
Draw a simple diagram of the human eye and label clearly the cornea, iris, pupil, ciliary muscles, eye-lens, retina, optic nerve and blind spot.
After testing the eyes of a child, the optician has prescribed the following lenses for his spectacles:
Left eye : + 2.00 D
Right eye : + 2.25 D
The child is suffering from the defect of vision called:
(a) short-sightedness
(b) long-sightedness
(c) cataract
(d) presbyopia
Name two animals having eyes:
at the front of the head.
The animals of prey have:
(a) two eyes at the front
(b) two eyes at the back
(c) two eyes on the sides
(d) one eye at the front and one on the side
We see advertisements for eye donation on television or in newspapers. Write the importance of such advertisements.
Define the following:
Power of accommodation
What are the functions of tears?
Differentiate between:
Yellow spot and Blind spot.
Name the following:
The type of lens used for correcting myopia.
Give Technical Term:
The nutritive layer of the eye which also presents reflection of light.
Mention, if the following statement is True or False
The least distance of distinct vision for the human eye is 25 cm
Write scientific reason.
The movie cannot be enjoyed if seat of a viewer is too close to the screen in the cinema.
Complete the paragraph by choosing the right options given below.
(minimum, near point, 25 cm, farthest, farthest distance, far point)
The _______ distance of an object from a normal eye, at which it is clearly visible without stress on the eye, is called the minimum distance of distinct vision. The position of the object at this distance is called the _______ of the eye, for a normal human eye, the near point is at _______. The _______ distance of an object from a human eye, at which it is clearly visible without stress on the eye is called _______ of distinct vision. The position of the object at this distance is called the _______ of the eye.
In a myopic eye, the image of the object is formed
The innermost layer of human eye is ______.
Given below is a cross section of the human eye. Match the structures marked (a) to (e) with their correct functions:
Example: (f) - 6. Holds the lens in position
| Cross section of Human Eye | Functions | |
 |
1. | Protects retina |
| 2. | Regulates the size of the pupil | |
| 3. | Alters the shape of the lens | |
| 4. | Keeps the lens moist | |
| 5. | Transmits nerve impulses to brain | |
| 6. | Holds the lens in position |
Name the following:
Kind of retinal cells sensitive to dim light.
