(n.) A defect of the eye or of a lens, in consequence of which the rays derived from one point are not brought to a single focal point, thus causing imperfect images or indistinctness of vision.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). astigmatism. Retrieved September 25, 2026, from http://smartdefine.org/astigmatism/definitions/1976614 |
| Chicago | Webster's. 2011. "astigmatism" http://smartdefine.org/astigmatism/definitions/1976614 (accessed September 25, 2026). |
| Harvard | Webster's 2011, astigmatism, Smart Define, viewed 25 September, 2026, <http://smartdefine.org/astigmatism/definitions/1976614>. |
| MLA | Webster's. "astigmatism" 27 May 2011. Web. 25 September 2026. <http://smartdefine.org/astigmatism/definitions/1976614> |