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प्रश्न
Given below is a diagram depicting a defect of the human eye? Study the same and answer the question that follow:
Give two possible reasons for this defect of the eye in human beings.
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उत्तर
The two possible reasons for myopia are the eyeball is lengthened from front to back and the lens is too curved.
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संबंधित प्रश्न
Which defect of vision can be rectified:
by using a concave lens?
A person cannot see the distant objects clearly (though he can see the nearby objects clearly). He is suffering from the defect of vision called:
(a) cataract
(b) hypermetropia
(c) myopia
(d) presbyopia
Describe the mechanism of focusing the image of a distant object in your eye when you raise your head after reading a book.
When do we consider a student sitting in the class to be myopic? List two causes of this defect. Explain using a ray diagram how this defect of eye can be corrected.
Differentiate between:
Short-sightedness and Long-sightedness.
With respect to human eye explain:
(i) How is the image formed on the retina?
(ii) How is the amount of light entering the eye-controlled?
(iii) What type of lens is used for the correction of ‘Long sight’ defect?
(iv) With the help of a ray, diagram show the defect of the eye and then its correction after the use of a lens.
Draw ray diagram showing myopic eye.
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.
Correlate the given sequence:
Hypermetropia : Convex lens : ______ : Concave lens
Observe the following diagram and answer questions following it:
- Identify the defect of vision shown.
- List its two causes.
- Name the type of lens used for the correction of this defect.
