- an irregularity in the curvature of a lens, including the lens of the eye, so that light rays from an object do not meet in a single focal point, resulting in an indistinct or distorted image
- distorted view or judgment, as because of bias
Origin of astigmatism; from Classical Greek a-, without + stigma (gen. stigmatos) a mark, puncture (see stick) + -ism
Origin of astigmatisma–1 + Greek stigma, stigmat-, point (from stizein, stig-, to tattoo; see steig- in Indo-European roots).
top: normal eye with light focusing on the retina
bottom: astigmatic eye with light focusing in different places on or in front of the retina
From a- (“not”) + stem of Ancient Greek στίγμα (stigma, “mark, point”) + -ism