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प्रश्न
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?
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उत्तर
(i)
1. Sclerotic
2. Choroid
3. Retina
4. Yellow spot or fovea
5. Optic nerve
6. Blindspot
7. Lens
8. Aqueous humour
9. Pupil
10. Iris
11. Vitreous humour
12. Cornea.
(ii) The function of the part marked ‘10’, the iris, is to regulate the amount of light that enters the eye so that too much light does not damage the delicate cells of the retina.
(iii) The person would not see because the sensations from the eye would not reach the brain.
संबंधित प्रश्न
Explain the terms ‘adaptation’ and ‘accommodation’ with reference to the eye.
What is Hypermetropia (far sightedness)?
What type of lens is used to correct Astigmatism?
Given below is a diagrammatic representation of a defect of the human eye:

(i) Identify the defect.
(ii) Mention two reasons for the above defect.
(iii) State how the defect can be rectified.
(iv) Name the part of the eye responsible for maintaining the shape of the eyeball.
Mention, if the following statement is True or False
Hypermetropia is a defect of the eye caused due to the eyeball elongation
A person cannot see distinctly objects kept beyond 2 m. This defect can be corrected by using a lens of power:
A student sitting at the back of the classroom cannot read clearly the letters written on the blackboard. What advice will a doctor give to her? Draw ray diagram for the correction of this defect.
State reasons for Myopia. With the help of ray diagrams, show the:
- image formation by a myopic eye, and
- correction of myopia using an appropriate lens.
Complete the following table by observing the given figures:
| Figure → | ![]() |
![]() |
| Points ↓ | ||
| (a) Name of the defect | ______ | ______ |
| (b) Position of the image | ______ | ______ |
| (c) Lens used to correct the defect | ______ | ______ |


