ASTIGMIA

Pronunciation (US): (GB):

I. (noun)

Sense 1

Meaning:

(optics) defect in an optical system in which light rays from a single point fail to converge in a single focal point

Synonyms:

astigmatism; astigmia

Classified under:

Nouns denoting stable states of affairs

Hypernyms ("astigmia" is a kind of...):

condition; status (a state at a particular time)

Domain category:

optics (the branch of physics that studies the physical properties of light)

Derivation:

astigmatic (of or relating to a defect in the eye or in a lens caused by a deviation from spherical curvature which prevents light rays from meeting at a common focus and so results in distorted images)

Sense 2

Meaning:

(ophthalmology) impaired eyesight resulting usually from irregular conformation of the cornea; common in nearsighted people

Synonyms:

astigmatism; astigmia

Classified under:

Nouns denoting stable states of affairs

Hypernyms ("astigmia" is a kind of...):

ametropia ((ophthalmology) faulty refraction of light rays in the eye as in astigmatism or myopia)

Domain category:

ophthalmology (the branch of medicine concerned with the eye and its diseases)

Hyponyms (each of the following is a kind of "astigmia"):

keratectasia (abnormal bulging of the cornea of the eye)

keratoconus (abnormal cone-shaped protrusion of the cornea of the eye; can be treated by epikeratophakia)