astigmatism
n//əˈstɪɡmətɪzm̩//astigmatism
(optics) A defect of a lens such that light rays coming from a point do not meet at a focal point so that the image is blurred.
(pathology) A disorder of the vision, usually due to a misshapen cornea, such that light does not focus correctly on the retina causing a blurred image.