Which lens is used to rectify myopia ?

Options

A. Convex
B. Concave
C. Plain
D. Cylindrical

Explanation

### Step-by-Step Solution:

1. **Understanding Myopia**: Myopia, also known as nearsightedness, is a condition where distant objects appear blurry while close objects can be seen clearly. This occurs because the light rays entering the eye focus in front of the retina rather than directly on it.

2. **Identifying the Problem**: In myopia, the image of distant objects is formed before it reaches the retina. Therefore, to correct this issue, we need a lens that can help diverge the light rays so that they focus correctly on the retina.

3. **Choosing the Right Lens**: The type of lens that is used to correct myopia is a concave lens. Concave lenses are diverging lenses that spread out light rays, allowing the image to be formed on the retina instead of in front of it.

4. **Conclusion**: Therefore, to rectify myopia, a concave lens is used. This lens helps to adjust the focal point of the light rays so that they converge on the retina, allowing for clear vision of distant objects.

### Final Answer:
The lens used to rectify myopia is a **concave lens**.