Question

What is presbyopia?

Answer 1

Answer:

The Eye - Lens grows through out the life and ciliary muscles lose the capacity to change the focal length of a big lens.

Due to this the near point of old aged person recedes . The near point becomes more than 25 cm. This Kind of Hypermetropia is experienced in old age therefore, called old age Hypermetropia or presbyopia.

Explanation:

Correction :-

Presbyopia is corrected by placing a convex lens before the eye.

If a person is suffering from myopia as well as Hypermetropia, the person needs bifocal lenses.

In bifocal lenses, the upper part is a concave lens to correct myopia and the lower part is a convex lens to correct Hypermetropia .

_______________________________

Answer 2

Answer:

presbyopia is vision defect when the ability of accommodations of the eye usually decreases with ageing.

This happens due to gradual wakening of ciliary muscles and diminishing flexibility of the eye lens. this effect can be seen in Aged people. sometimes a person may suffer from both Myopia and Hypermetropia with ageing..

hope it helps

#Ravalika Rajula

: )