astigmia vs optics

astigmia and optics both are nouns.

Word	Noun	Adjective	Verb	Adverb
astigmia	Yes	No	No	No
optics	Yes	No	No	No

astigmia (noun)	optics (noun)
(optics) defect in an optical system in which light rays from a single point fail to converge in a single focal point	optical properties
(ophthalmology) impaired eyesight resulting usually from irregular conformation of the cornea; common in nearsighted people	the branch of physics that studies the physical properties of light