To solve the question, we need to analyze each option based on the principles of optics, particularly focusing on the concepts of power of lenses, far point, and near point.
### Step-by-Step Solution:
1. **Understanding Option A:**
- The statement is: "If the far point goes ahead, the power of the divergent lens should be reduced."
- When the far point of a person’s vision shifts closer (moves ahead), it indicates that the person is becoming more myopic (nearsighted).
- To correct this, a diverging lens (concave lens) is required.
- The power of a lens (P) is given by the formula \( P = \frac{1}{f} \), where \( f \) is the focal length.
- If the far point moves ahead, the focal length of the required lens increases (becomes less negative), leading to a decrease in power.
- **Conclusion:** Option A is correct.
2. **Understanding Option B:**
- The statement is: "If the near point goes ahead, the power of the convergent lens should be reduced."
- If the near point shifts further away, it indicates that the person has difficulty seeing objects up close (hyperopia or farsightedness).
- To correct this, a converging lens (convex lens) is required.
- As the near point moves away, the focal length of the required lens decreases, which means the power of the lens must increase.
- **Conclusion:** Option B is incorrect.
3. **Understanding Option C:**
- The statement is: "If the far point is 1 meter away from the eye, a divergent lens should be used."
- If the far point is at 1 meter, this indicates that the person can see objects clearly only up to 1 meter, which is a case of myopia.
- A diverging lens is indeed required to correct this vision.
- Since the far point is at 1 meter, the lens must have a negative focal length, confirming the use of a divergent lens.
- **Conclusion:** Option C is correct.
4. **Understanding Option D:**
- The statement is: "If the near point is 1 meter away from the eye, a divergent lens should be used."
- If the near point is at 1 meter, this indicates that the person has difficulty seeing objects that are closer, which is a case of hyperopia.
- To correct this, a converging lens (convex lens) is required, not a divergent lens.
- **Conclusion:** Option D is incorrect.
### Final Answer:
The correct options are **A and C**.
