Question

an old person is not clearly able to see nearby objects as well as distant objects.

1) from which defect is he suffering from?

2) explain which lens should be used to correct this defect?why?

Answer 1

1. The person is suffering from the defect named Presbyopia.
2. Bifocal lens of suitable focal length in which the upper lens is a concave lens , which is used for seeing distant objects and the lower lens is a convex lens, which is used for seeing nearby objects