astigmatism, astigmia
(noun) (optics) defect in an optical system in which light rays from a single point fail to converge in a single focal point
astigmatism, astigmia
(noun) (ophthalmology) impaired eyesight resulting usually from irregular conformation of the cornea; common in nearsighted people
Source: WordNet® 3.1
astigmatism (countable and uncountable, plural astigmatisms)
(optics) 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.
(pathology) 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.
• astigmia
Source: Wiktionary
A*stig"ma*tism, n. Etym: [Gr. astigmatisme.] (Med. & Opt.)
Definition: A defect of the eye or of a lens, in consequence of which the rays derived from one point are not brought to a single focal point, thus causing imperfect images or indistictness of vision.
Note: The term is applied especially to the defect causing images of lines having a certain direction to be indistinct, or imperfectly seen, while those of lines transverse to the former are distinct, or clearly seen.
Source: Webster’s Unabridged Dictionary 1913 Edition
19 November 2024
(noun) bushy plant of Old World salt marshes and sea beaches having prickly leaves; burned to produce a crude soda ash
Wordscapes is a popular word game consistently in the top charts of both Google Play Store and Apple App Store. The Android version has more than 10 million installs. This guide will help you get more coins in less than two minutes of playing the game. Continue reading Wordscapes: Get More Coins