Which ametropia is characterized by the cornea being too strong or too weak?

Refractive ametropia refers to a condition in which the eye's ability to focus light is compromised due to the refractive power of the cornea or lens being either too strong or too weak. This can result in vision problems such as myopia (nearsightedness) or hyperopia (farsightedness).

In this context, when the cornea is too strong, it can cause light rays to focus in front of the retina, leading to myopia. Conversely, if the cornea is too weak, it results in hyperopia, where light rays focus behind the retina. Since refractive ametropia encompasses these variations in the eye's refractive status related to the corneal curvature, it is the most relevant classification for the question asked.

The other types of ametropia—axial, simple astigmatism, and compound astigmatism—relate to variations in the length of the eyeball or specific irregularities in the shape of the cornea rather than general strength variations of the cornea itself.