A doctor prescribes a person (i) power of -5 D for distant vision correction (ii) power of +2 D for near vision. Determine the focal length of both the parts of corrective lens.

Explanation

To solve the problem, we need to determine the focal lengths of two corrective lenses based on the powers prescribed by the doctor.

### Step-by-Step Solution:

1. **Understanding Power and Focal Length**:
The power \( P \) of a lens is related to its focal length \( f \) by the formula:
\[
P = \frac{1}{f}
...