Medicine & BodyGreek → English
Astigmatism
/əˈstɪɡmətɪzəm/noun
A defect of the eye in which uneven curvature stops light focusing to a single point.
The Greek roots
ἀ-
a-
not, without
στίγμα
stígma
point, puncture mark
Literally: “no point”
The story of the word
στίγμα is the mark a sharp stylus leaves, and with alpha privative the word says the light never comes to a point. In an astigmatic eye the cornea is curved more steeply in one direction than another, so lines running one way sit sharp while lines at right angles blur. Thomas Young measured the defect in his own eyes in 1801, and the name came a few decades later out of the circle around William Whewell, who also gave English the word scientist.
- How it travelled
- Ancient Greek → scientific coinage → English
- First recorded
- 1840s
Same family
stigmastigmatastigmatize
In a sentence
Her astigmatism makes headlights smear into streaks at night.