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प्रश्न
Name the part of the eye:
which changes the focal length of eye-lens.
उत्तर
The ciliary muscles change the focal length of the eye lens.
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संबंधित प्रश्न
Name two parts of the eye which refract light rays (or bend light rays).
Fill in the following blank with suitable word:
To bring light from a near object to a focus on the retina of the eye, the convex eye-lens need to be made....................
To focus the image of a nearby object on the retina of an eye:
(a) the distance between eye-lens and retina is increased
(b) the distance between eye-lens and retina is decreased
(c) the thickness of eye-lens is decreased
(d) the thickness of eye-lens is increased
The size of the pupil of the eye is adjusted by:
(a) cornea
(b) ciliary muscles
(c) optic nerve
(d) iris
Name the following:
White part of the eye.
For a normal human eye the near point is at _______.
Shylesh is a school-going kid studying standard VIII. He is crazy about playing video games on mobile phones. After a couple of months, his eyes turned red and he felt severe pain in his eyes. His science teacher enquired about this and advised his parents to take him to an eye doctor.
- How does excessive usage of mobile phone affect our eyes?
- What are the values shown by the teacher?
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?
 |
 |
 |
 |
| (A) | (B) | (C) | (D) |
Eyes of the nocturnal birds have large cornea and a large pupil. How does this structure help them?
State the functions of the following:
Ciliary muscles
