Explanation:

- Myopia, or short-sightedness, occurs when the eye focuses images in front of the retina.

- Corrected by lenses: Lenses help in refocusing light onto the retina.

- Option 1: Convex lens

- Used for far-sightedness (hyperopia).

- Shapes light to focus behind the retina.

- Option 2: Concave lens

- Corrects myopia.

- Spreads out light rays to focus on the retina.

- Option 3: Cylindrical lens

- Corrects astigmatism.

- Has a different curvature in each meridian.

- Option 4: None of the above

- Not applicable since concave lenses are used.