A ___ lens is used to correct myopia and a ___ lens is used to correct hypermetropia.

The correct option is D

concave, convex

Explanation for the correct option:

Myopia

1. Myopia or near-sightedness is the condition where the eye loses its ability to focus on far-off objects.
2. The lens of the myopic eye falls short of focusing the light onto the retina i.e., its focal length is shorter than the distance between lens and retina.
3. A concave lens lengthens the focal length of the lens of the eye and helps it to form the image on the retina.
4. Thus, a concave lens helps correct myopia.

Hypermetropia

1. Hypermetropia or far-sightedness is the condition where the eye loses its ability to focus on very near objects.
2. The lens of the hypermetropic eye focuses the light away from the retina i.e., its focal length is longer than the distance between lens and retina.
3. A convex lens reduces the focal length and thus helps form the image on the retina.
4. Thus, a convex lens helps correct hypermetropia.

Hence, option D is correct.