A person cannot see distinctly objects kept beyond 2 m. This defect can be corrected by using a lens of power
(a) + 0.5 D
(b) – 0.5 D
(c) + 0.2 D
(d) – 0.2 D
Answer
The person is suffering from myopia .
Myopia can be corrected by using a concave lens .
Since, 2m is the last point of vision, let us assume the focal length of the lens to be 2m.
P=1/f = -½= -0.5D
So, the correct answer is (b)