Judged: two independent readers; copy check clear.
astigmatism
astigmatism Astigmatism is a defect in the eye’s refracting system in which light from a single point is not focused to a single point on the retina.
Astigmatism is a defect in the eye’s refracting system in which light from a single point is not focused to a single point on the retina. In regular astigmatism, this commonly happens because a refracting surface such as the cornea is unevenly curved in different directions, so lines in different orientations are not seen equally clearly at the same time.