Question

An old person finds it difficult to see nearby objects comfortably and distinctly without
corrective eye glasses.
(a) What defect of vision is he suffering from? What is it?
(b) List two causes for the development of this defect.
(c) What kind of lens will be required to see clearly the nearby as well as distant objects? Give
reasons.
(d) How is the eye defect of old person differing from near-sightedness and far-sightedness?

Answer 1

a) Presbyopia.

b) This defect is caused due to aging which results in weakening of ciliary muscles

Decrease in the flexibility of eye lenses.

c) Bifocal lens . upper half is made of concave lens and lower half is made of convex lens which helps old people to see both near and faraway objects .

HOPE IT HELPS

Answer 2

he is suffering from presbyopia

the two cause of defect of this vision are gradual weakening of cilliary muscle and diminished flexibility of eye lens

use of bifocal lens