9 Grammatical Pitfalls
astigmia a·stig·mi·a (ə-stĭg'mē-ə)
astigmatism a·stig·ma·tism (ə-stĭg'mə-tĭz'əm)
A condition in which unequal curvatures along the different meridians in one or more of the refractive surfaces of the eye cause the rays from a light source not to be focused at a single point on the retina. Also called astigmia.