Question
A person cannot see distinctly objects kept beyond 2m. This defect can be corrected by using a lens of power:
- +0.5D
- -0.5D
- +0.2D
- -0.2D
✓
Answer
- -0.5D
Explanation: This person is suffering from myopia. He needs a concave lens and hence power would be in negative.
$\text{P}=\frac{1}{\text{f}}=\frac{1}{2\text{m}}=0.5\text{D}$
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