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प्रश्न
Given below is a diagram showing a defect of vision. Name the defect of vision and draw an accurately labelled diagram to correct this defect.
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उत्तर
Name of defect: Farsightedness or hypermetropia
Correction of Farsightedness:
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संबंधित प्रश्न
Given below is a diagram showing a defect of human eye. Study it and answer the following questions.
(i) Name the defect shown in the figure.
(ii) Give reason for this defect of eye in human being.
(iii) Name the type of lens used to correct the eye defect.
What is myopia?
Do you know that the corneal-impairment can be cured by replacing the defective cornea with the cornea of the donated eye? How and why should we organise groups to motivate the community members to donate their eyes after death?
What is the other name for
myopia
Name the defect of vision in which the eye-lens loses its power of accommodation due to old age.
Name the defect of vision which makes the eye-lens cloudy resulting in blurred vision.
Name any two defects of vision which can be corrected by using spectacles.
Your friend can read a book perfectly well but cannot read the writing on blackboard unless she sits on the front row in class.
- Is she short-sighted or long-sighted?
- What type of lenses-converging or diverging-would an optician prescribe for her?
Your friend can read a book perfectly well but cannot read the writing on blackboard unless she sits on the front row in class.
What type of lenses-converging or diverging-would an optician prescribe for her?
A student sitting in the last row of the class-room is not able to read clearly the writing on the blackboard.
How can this defect by corrected?
What are the two most common defects of vision (or defects of eye)? How are they corrected?
Name the defect of vision which can be corrected by a converging lens. Show clearly by a ray diagram how the lens corrects the defect.
Explain with the help of labelled ray-diagram, the defect of vision called hypermetropia, and hot it is corrected by a lens.
A short-sighted person has a near point of 15 cm and a far point of 40 cm.
(a) Can he see clearly an object at a distance of:
(i) 5 cm?
(ii) 25 cm?
(iii) 50 cm?
(b) To see clearly an object at infinity, what kind of spectacle lenses does he need?
A person can read a book clearly only if he holds it at an arm's length from him. Name the defect of vision:
- if the person is an old man
- if the person is a young man
Name the following:
The eye defect caused due to shortening of the eye ball from front to back.
Differentiate between members of the following pair with reference to what is asked in the bracket.
Rods and cones (sensitivity).
Name an old age eye defect. What happens in it?
A student has difficulty reading the blackboard while sitting in the last row. What could be the defect the child is suffering from? How can it be corrected?
Choose the odd one out from the following terms and name the category to which the others belong.
Endolymph, Tympanic membrane, Semi-circular canal, Blind spot
The diagram alongside represents a section of a mammalian eye.
(i) Label the parts 1 to 5 of the diagram.
(ii) State the function of the parts labelled 4 and 5.
(iii) With the help of a diagram show the short sightedness.
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.
Have a look at the posture of this woman who is reading a book and answer the questions which follow:
What kind of looking glasses she needs?
In what two whys is a yellow spot different from the blind spot?
Name an old age eye defect. Why is it caused?
Differentiate between:
Short-sightedness and Long-sightedness.
Explain the Term: Astigmatism
Explain the Term: Cataract
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.
Mention, if the following statement is True or False
Hypermetropia is a defect of the eye caused due to the eyeball elongation
Due to elongation of _______ and increase in curvature of the eye lens, a person cannot see distant objects clearly.
A person cannot see distinctly objects kept beyond 2 m. This defect can be corrected by using a lens of power:
A person needs a lens of power –4.5 D for correction of her vision.
- What kind of defect in vision is she suffering from?
- What is the focal length of the corrective lens?
- What is the nature of the corrective lens?
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.
A person is unable to see clearly a poster fixed on a distant wall. He however sees it clearly when standing at a distance of about 2 m from the wall.
- Draw ray diagram to show the formation of image by his eye lens when he is far away from the wall.
- List two possible reasons of this defect of vision.
- Draw ray diagram to show the correction of this defect using appropriate lens.
