Question

Write in breif about defect of human eye?

Answer 1

*hypermetropia : also known as farsightedness .... in this defect the person in not able to see only near objects clearly.

This defect occur when the eyeball is too short .

In this defect image is formed outside the retina ..

to correct this defect convex lense is used..

*Myopia : also known as short-sightedness in this person is not able to see far objects clearly .

this is due to when eyeball is too long.

in this defect image is formed in fornt of retina.

*Presbiopia : in this defect the person is not able to far objects as well as near objects , this defect mainly occurs in old age

due to the weakning of ciliary muscles

this is corrected by using bi- focal lense.