What is the common term for a condition where the cornea has abnormal shape leading to distorted vision?

The condition characterized by an abnormal shape of the cornea that leads to distorted vision is called keratoconus. In keratoconus, the cornea thins and bulges into a cone-like shape, which disrupts the normal focusing of light onto the retina. This results in significant visual distortion and can cause symptoms such as blurred or irregular vision.

While astigmatism also involves a distorted vision due to irregularities in the cornea's shape, it typically refers to general corneal irregularities that can be present without the cornea adopting the characteristic conical shape seen in keratoconus. Myopia and hyperopia, on the other hand, relate to refractive errors where the eye either focuses images in front of or behind the retina, respectively, rather than issues with the corneal shape itself. Therefore, keratoconus specifically describes the unique abnormal corneal deformation leading to the noted visual disturbances.