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प्रश्न
Have a look at the posture of this woman who is reading a book and answer the questions which follow:
What are the two conditions shown in sections A and B of the eye as applicable to her?
उत्तर
A-Normal eye, B-Myopia
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संबंधित प्रश्न
In a Std. X class out of 40 students 10 students use spectacles, 2 students have positive power and 8 students have negative power of lenses in their spectacles.
Answer the following questions:
(1) What does the negative power indicate?
(2) What does the positive power indicate?
(3) Generally which type of spectacles do most of the students use?
(4) What defect of eyesight do most of the students suffer from?
(5) Give two possible reasons for the above defect.
The kind of lens required to correct Myopia
the biological/technical terms for the lens of eye losing flexibility resulting in a kind of long-sightedness in middle aged people.
Which defect of vision can be rectified:
by using a concave lens?
What is the other name for
myopia
What is the other name for
hypermetropia
Name any two defects of vision which can be corrected by using spectacles.
What is short-sightedness? State the two causes of short-sightedness (or myopia). With the help of ray diagrams, show:
(i) the eye-defect short-sightedness.
(ii) correction of short-sightedness by using a lens.
A person having short-sight cannot see objects clearly beyond a distance of 1.5 m. What would be the nature and power of the corrective lens to restore proper vision?
What is long-sightedness? State the two causes of long-sightedness (or hypermetropia). With the help of ray diagrams, show:
(i) the eye-defect long-sightedness.
(ii) correction of long-sightedness by using a lens.
A young man has to hold a book at arm's length to be able to read it clearly. The defect of vision is:
(a) astigmatism
(b) myopia
(c) presbyopia
(d) hypermetropia
The picture given here shows a person wearing 'half-moon' spectacles. What sort of eye-defect do do you think he has? Why are these particular spectacles useful to him?
What is Hypermetropia (far sightedness)?
Select the odd one in the following series:
Endolymph, Tympanic membrane, Semi-circular canal, Blind spot.
In what two whys is a yellow spot different from the blind spot?
Choose the Odd One Out:
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.
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.
Name the following:
Two kinds of accomodations.
