A person needs a lens of power, -5.5 D for correcting his distant vision. For correcting his near vision, he needs a lens of power, + 1.5 D. What is the focal length of the lens required for correcting :
(a) distant vision ?
(b) near vision ?
What type of lens is being used for correcting (i) distant vision, and (ii) near vision ?

Explanation

To solve the problem, we need to find the focal lengths of the lenses required for correcting distant and near vision, and identify the types of lenses used.

### Step-by-Step Solution:

**Step 1: Understanding the Power of the Lens**
- The power (P) of a lens is given in diopters (D) and is related to its focal length (f) in meters by the formula:
\[
P = \frac{1}{f}
...