Question

A person cannot see the object beyond 3 metre distinctively.State the nature and focal length of the lens required to correct this defect of vision.

Answer 1

its power will be in positive because the image formed beyond the retina is hypermetropia or farsightedness.

Answer 2

this case of farsightedness I.e hypermetropia .
A convex lens should be used.
focal length wil be 3m.
power of lens 1/f=1/3.=0.333...
I HOPE IT IS USEFUL!