Science
It is observed that the power of an eye to see nearby objects as well as far off objects diminishes with age.
(i) Give reason for the above statement.
(ii) Name the defect that is likely to arise in the eyes in such a condition.
(iii) Draw a labelled ray diagram to show the type of corrective lens used for restoring the vision of such an eye.
Human Eye
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Answer
(i) The power of an eye to see nearby objects as well as far off objects diminishes with age because the power of accommodation of the eye usually decreases with ageing due to weakening of ciliary muscles and decrease in flexibility of eye lens.
(ii) The defect that is likely to arise in the eyes in such a condition is Presbyopia. For most people, the near point gradually recedes away. They find it difficult to see nearby objects comfortably and distinctly without corrective eye-glasses.
(iii) Presbyopia can be corrected by using a convex lens as shown in the diagram below:
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