Answer:
To correct the problem of farsightedness
Explanation:
In the problem of farsightedness, an object which is far away look clear while an object which is near to eye lens it looks blurr as the image of the object is formed behind the retina.
In order to converge all the light rays passing through an eye lens at its retina a convex lens is used. A convex lens enables the meeting of rays at the retina and thus they need not to travel beyond retina to meet at some point.
