The eye defect caused by an uneven curvature of the cornea or lens or both is

A.

myopia

B.

presbyopia

C.

astigmatism

D.

hypermetropia

Correct answer is C

Astigmatism is a common refractive error of the eye that occurs when the cornea or lens has an irregular shape. In a normal eye, the cornea and lens have a smooth, evenly curved surface, similar to a sphere. However, in astigmatism, the cornea or lens may be more curved in one direction than the other, resulting in a refractive error.