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प्रश्न
Name an old age eye defect. Why is it caused?
उत्तर १
Presbyopia is an age-old eye defect. In this condition, the lens loses flexibility resulting in far-sightedness.
Cataract is also very common in old people, the cornea becomes opaque and the vision is cut down even to blindness.
उत्तर २
Hypermetropia. It is caused due to flattening of the eye lens (Also presbyopia in which lens looses flexibility).
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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.
A person with a myopic eye cannot see objects beyond 1.2 m distinctly. What should be the type of the corrective lens used to restore proper vision?
Name any two defects of vision which can be corrected by using spectacles.
A person suffering from the eye-defect myopia (short-sightedness) can see clearly only up to a distance of 2 metres. What is the nature and power of lens required to rectify this defect?
Differentiate between members of the following pair with reference to what is asked in the bracket.
Rods and cones (sensitivity).
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?
State the main functions of the following:
Tears
Distinguish between the following pair of words:
Myopia and hypermetropia
Choose the correct answer :
Presbyopia is a disease of _____________
Anuja cannot see the blackboard writing but she can see nearby things.
(a) What is the eye defect she is suffering from?
(b) State the possible reason for her defect.
(c) How is it corrected
Name the common defects of the eye.
Give Reason:
Why do we see clearly in the central region of the retina?
Give Reason:
When you enter into a dark room from bright because of sunlight, you can not see things for a few seconds.
Complete the following sentence with appropriate word :
An inability to focus on nearby objects due to loss of elasticity of the lens with age is called Iris.
Mention, if the following statement is True or False
Hypermetropia is a defect of the eye caused due to the eyeball elongation
Choose the Odd One Out:
Assertion: Concave mirrors are used as reflectors in torches, vehicle head lights and in search lights.
Reason: When an object is placed beyond the center of curvature of a concave mirror, the image formed is real and inverted.
Name the following:
Two kinds of accomodations.
