what is the difference between myopia and presbyopia - Science - The Human Eye and the Colourful World

Question

what is the difference between myopia and presbyopia?

C. Muthu Kumari · Accepted Answer

Dear Student,
Myopia is a defect of vision
in which a person clearly sees all the nearby objects but is unable
to see the distant objects comfortably A
myopic eye forms the image of a distant object in front of its
retina
Myopia is caused
by
(i)Increase in curvature of
the lens

(ii)Increase in length of the
eyeball

Myopia is corrected using a concave
lens

Presbyopia
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

It
may also happen that a person suffers from both myopia and
hypermetropia This type of defect can be corrected by using
bi-focal lenses A bifocal lens consists of both convex lens (to
correct hypermetropia) and concave lens (to correct
myopia)

Hope
you got the answer!
@Deni, Good answer, we really
appreciate your contribution to this forum, Keep up the good
work!

Cheers!

Name	Myopia	Presbyopia
Defect	Defect of vision where an eye cannot see object clearly beyond a certain distance, through it can see nearby object clearly.	Loss of power of accommodation of the eye. It occurs in old age due to the gradual weakening of the ciliary muscles
Correction	Using concave lens.	A bi-focal lens consists of both convex and concave lenses.