A short sighted person cannot see clearly beyond `2 m`. Calculate power of the lens required to correct his eye to normal vision.

Explanation

To solve the problem of calculating the power of the lens required for a short-sighted person who cannot see clearly beyond 2 meters, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Condition**:
A short-sighted person (myopic) can only see objects clearly up to a distance of 2 meters. This means that the farthest point they can see clearly is at 2 meters.

2. **Determining the Focal Length**:
To correct this vision, we need to bring the image of distant objects (which are at infinity) to a point where the person can see them clearly. The lens needs to create an image at the person's farthest clear vision point, which is at 2 meters.
- The focal length (f) of the lens required can be considered as the negative of the distance at which the person can see clearly. Therefore,
\[ f = -2 \text{ m} \]

3. **Calculating the Power of the Lens**:
The power (P) of a lens is given by the formula:
\[ P = \frac{1}{f} \]
where \( f \) is in meters. Substituting the focal length:
\[ P = \frac{1}{-2} = -0.5 \text{ diopters} \]

4. **Conclusion**:
The power of the lens required to correct the vision of the short-sighted person is \(-0.5\) diopters.

### Final Answer:
The power of the lens required to correct the vision is \(-0.5\) diopters.

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