It is an alteration of vision due to the fact that the eye does not have the same curvature in all its axes, usually due to an alteration of the cornial curvature. Typically causes headache, difficulty focusing at different distances, and blurred near and far vision.
Normally this astigmatism does not vary with age, once the age of 20 is reached. When astigmatism varies significantly, it is necessary to think of a degenerative disease of the cornea (corneal ectasia), or the presence of a cataract.
The presence of a family history of elevated astigmatism and / or lazy eye are risk factors for having this ametropia.