Question

Sharada cannot see the board clearly when she sits in the last bench in the class
room.
(a) What is this condition called?
(b) Name the type of lens often required by the persons suffering from this defect.
(c) Draw labelled diagram of the defect and its correction.
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Answer 1

Answer:-

a) The condition given in the question is called nearsightedness or Myopia.

b) The type of lens that is required by the person suffering from this defect is concave lens.

c) The answer is in the attached photo.

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Myopia:-

• Myopia happens when the person is able to see near objects perfectly but is not able to see far objects.

• This can happen due to certain reasons:-

1. Excessive curvature of the eyelens
2. And elongation of eyeball

• In this defect the light rays falling from the object does not reach the retina to form the image. The image in this condition is formed in front of the retina.

• This can can be corrected only with the concave lens which helps in diverging the light rays so that when it reaches the eyelens it can converged to a proper position at a point on retina.

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