Answers

  • Brainly User
2016-01-09T22:27:36+05:30
Bifocal Lens..........!!!!!!!!
0
2016-01-09T23:36:06+05:30
Presbyopia basically occurs at old age due to the weakening of ciliary muscles which cannot adjust the focal length of the lens. To old people it may occour as hypermetropia. So convex lens could be used. But sometimes a person may have both myopia and hypermetropia. So in such cases bifocal or varifocal lens is used. It has both concave n convex lenses.
0
thank you there was a confusion for the convex lense thanx for removing it
My pleasure.