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प्रश्न
What are the functions of tears?
उत्तर
The functions of tears:
(i) To lubricate the surface of the eye.
(ii) To wash away dust particles.
(iii) To help in killing germs.
(iv) To communicate emotions.
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संबंधित प्रश्न
Differentiate between: Rods and cones
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 |
What is the function of the lens in the human eye?
Name the part of the retina which is insensitive to light.
Describe and explain, how a normal eye can see objects lying at various distances clearly.
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
A person got his eyes tested. The optician's prescription for the spectacles reads:
Left eye: − 3.00 D
Right eye: − 3.50 D
The person is having a defect of vision called:
(a) presbyopia
(b) myopia
(c) astigmatism
(d) hypermetropia
With both eyes open, a person's field of view is about:
(a) 90°
(b) 150°
(c) 180°
(d) 360°
State the main functions of the following:
Coronary Artery
Write whether the following is true or false:
Rods are the receptor cells in the retina of the eye sensitive to dimlight.
Choose the correct answer.
Colour is detected by ____________
A small hole of changing diameter at the centre of Iris is called _______.
The image of the object in the human eye is formed on the cross screen.
Write an Explanation.
Power of accommodation
Eyes of the nocturnal birds have large cornea and a large pupil. How does this structure help them?
______ is a transparent layer.
Arrange and rewrite the term in group in correct order to be in a logical sequence, beginning with the term that is underlined:
Pupil, Aqueous humour, Retina, Vitreous humour.
Which of the following is responsible for the adjustment of the size of pupil?
Match the terms in column I with those in column II and write down the matching pairs.
| Column I | Column II | ||
| (i) | Conjunctiva | (a) | Viral infection |
| (ii) | Cornea | (b) | Ciliary body |
| (iii) | Choroid | (c) | Spiral-shaped |
| (iv) | Cochlea | (d) | Transparent epithelium |
| (v) | Conjunctivitis | (e) | Suspensory ligament |
| (f) | Contains melanin | ||
| (g) | Transparent but appears black |
