astigmatism
noun
- refractive error characterized by the optics of the eye to focus a point object into a sharp focused image on the retina, has_symptom blurred vision.
- refractive error in optics
Wiktionary
Pronunciation: /əˈstɪɡmətɪzm̩/
noun
Etymology: From a- (negative prefix) + stem of Ancient Greek στίγμα (stígma, “mark, point”) + -ism. Coined by English polymath William Whewell in 1846.
- 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.
- 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.