Chapter 25 - Vision and Optical Instruments - Learning Path Questions and Exercises - Exercises - Page 871: 9

a). $(2)$ farsightedness b). $(1)$ converging lens c). Power = $+3.3D$

a). The correct answer is (2), Since he cannot focus on close objects, he is farsighted. b). The correct choice is (1). Since he is farsighted, he needs a converging lens to correct his vision. c). $do=+0.25m$ $di=-1.5m$ $P=\frac{1}{f}=\frac{1}{do}+\frac{1}{di}=\frac{1}{0.25}+\frac{1}{-1.5}=+3.3D$