astigmatism
UK[əˈstɪɡmətɪzəm]US[əˈstɪɡməˌtɪzəm]
n
A defect in the eye or in a lens that prevents light from focusing correctly, resulting in a blurred image.
Morpheme Breakdown
a
stigma
ism
a
without
stigma
point
ism
condition
Etymology
The term astigmatism is a modern scientific construction from Greek elements, literally describing the condition of being "without a point." The key component, stigma, derives from the Greek verb stizein, meaning "to prick" or "to mark," which gave stigma the sense of a pointed mark or spot. In optical science, a perfect focal point is crucial for clear vision. Therefore, astigmatism logically denotes a refractive error where light rays fail to converge into a single sharp point on the retina. The suffix -ism systematically converts this descriptive phrase into a noun naming the specific medical condition.
Analysis
Structure: a (without) + stigma (point) + ism (condition)
a: Greek origin, a prefix meaning "without" or "not".
stigma: Greek origin, meaning "point", "mark", or "puncture".
ism: Greek/Latin origin, a suffix forming nouns indicating a state, condition, or doctrine.
Examples
He wears special contact lenses to correct his astigmatism.
A comprehensive eye exam can diagnose astigmatism.
The curvature of her cornea causes a slight astigmatism.