Question

Define myopia ,hypermetropis and presbyopia.


ans. correctly otherwise I'll help u....​

Answer 1

Answer:

myopia is the defect that I cannot see see the foreign objects

hypermetropia means the defect in which the person cannot see the near objects to correct this defect we have to use con wax

presbyopia means the person cannot see e neither near nor far objects

Answer 2

Answer:

Explanation:

Myopia :-

In myopia, distant objects are not clearly visible. It is corrected by using concave lens.

Hypermetropia :-

In hypermetropia, nearby objects are not clearly visible. It is corrected by using convex lens.

Presbyopia :-

Presbyopia arises due to weakening of ciliary muscles in old age. It can be corrected by using bifocal lens.

Important terms :-

Range of vision - The distance between the far point and near point of the eye is known as range of vision'

Persistence of vision - The time period for sensation of an objects continues in eyes is known as persistence of vision.

It is 1/16th of second.