Match the columns in the following table and explain them.

Explanation

i. Farsightedness `rarr` Far away object can be seen clearly `rarr` Convex lens
Explanation: In farsightedness, the human eye can see far away object clearly but cannot see nearby objects distinctly. To correct this defect, a convex lens with proper focal length is used.
ii. Presbyopia `rarr` Problem of old age `rarr` Bifocal lens.
Explanation: The ability of the muscles near the eye lens to change the focal length of the lens decreases with age. This defect is known as presbyopia. In this defect, sometimes people suffer from both nearsightedness and farsightedness. Therefore, bifocal lenses are required to correct this defect.
iii. Nearsightedness `rarr` Nearby object can be seen clearly `rarr` concave lens Explanation: In nearsightedness, the human eye can see nearby objects clearly but cannot see far away objects distinctly. To correct this defect, a concave lens with proper focal length is used.