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प्रश्न
Fill in the following blank with suitable word:
To bring light from a distant object to a focus on the retina of the eye, the convex eye-lens needs to be made..........
उत्तर
To bring light from a distant object to a focus on the retina of the eye, the convex eye-lens needs to be made thinner.
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संबंधित प्रश्न
A person got his eyes tested by an optician. The prescription for the spectacle lenses to be made reads :
Left eye : +2.50 D
Right eye : +2.00 D
State whether these lenses are thicker in the middle or at the edges.
What are rods and cones in the retina of an eye? Why is our night vision relatively poor compared to the night vision of an owl?
What happens to the size of pupil of our eye (i) in dim light (ii) in bright light?
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
Name two animals having eyes:
one the sides of the head.
Sometimes you remember a vivid picture of a dream you saw. What is the role of your eyes in this experience?
The diagram alongside represents a certain defect of vision of the human eye.
(i) Name the defect.
(ii) Describe briefly the condition in the eye responsible for the defect.
(iii) Redraw the figure by adding a suitable lens correcting the defect. Label the parts through which light-rays pass.
(iv) What special advantage do human beings derive in having both eyes facing forward?
We cannot distinguish colours in dim light. Explain giving suitable reasons.
Name the following:
The circular opening enclosed by iris.
Name the following:
The fibres which collectively hold the lens in position.
