Question

write short note on presbyopia in 2 mark question . plz answer those who know​

Answer 1

Explanation:

Presbyopia is the gradual loss of your eyes' ability to focus on nearby objects. It's a natural, often annoying part of aging. Presbyopia usually becomes noticeable in your early to mid-40s and continues to worsen until around age 65.

Answer 2

Explanation:

$\huge{\underline{\underline{Presbyopia→}}}$

$→$The power of accommodation of the eye usually decreases with ageing. For most people, the near point gradually recedes away. This defect is also called old-sightedness(far-sightedness of old people).

1. Presbyopic person finds it difficult to see nearby objects comfortably and distinctly.
2. This defect usually occurs in old age because of gradual weakening of the ciliary muscles and diminishing flexibility of the eye lens and thereby ciliary muscles lose their elasticity and so cannot change the focal length of the eye lens effectively.

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Sometimes, a person may suffer from both myopia and hypermetropia.In such cases, the defect can be corrected by using the spectacles having bifocal lenses such that the lower portion of the bifocal lens is a convex lens so as to focus the nearby objects and the upper portion of the bifocal lens is a concave lens so as to focus the distant objects.

HOPE IT HELPS.