Question

1. Match the columns in the following
table and explain them.
&
Column 1
Column 2
Column 3
Farsightedness
Nearby object
can be seen
clearly
Bifocal
lens
Far away
Presbyopia
Concave
lens
object can be
seen clearly
Problem of old
age
Nearsightedness
Convex
lens​

Answer 1

the last page is :-

Presbyopia: This is a common defect of

vision, which generally occurs at old age. A person suffering from this type of defect of vision cannot see nearby objects clearly and distinctively. A presbyopic eye has its near point greater than 25 cm and it gradually increases as the eye becomes older.

Presbyopia is caused by the

1. weakening of the ciliary muscles

2. reduction in the flexibility of the eye lens

It can be corrected using bifocal lens.