Main Entry: astig·ma·tism

Pronunciation: \ə-ˈstig-mə-ˌti-zəm\

Function: noun

Date: 1846

1 : a defect of an optical system (as a lens) causing rays from a point to fail to meet in a focal point resulting in a blurred and imperfect image
2 : a defect of vision due to astigmatism of the refractive system of the eye and especially to corneal irregularity
3 : distorted understanding suggestive of the blurred vision of an astigmatic person