examination by means of an astigmatoscope.
Also called astigmia [uh-stig-mee-uh] /əˈstɪg mi ə/ (Show IPA). Ophthalmology. a refractive error of the eye in which parallel rays of light from an external source do not converge on a single focal point on the retina. Optics. an aberration of a lens or other optical system in which the image of a point is […]
any plant of the genus Astilbe, of the saxifrage family, having spirelike clusters of small white, pink, or reddish flowers. noun any perennial saxifragaceous plant of the genus Astilbe of E Asia and North America: cultivated for their ornamental spikes or panicles of pink or white flowers
moving or , especially with much activity or excitement: The field was astir with small animals, birds, and insects. up and about; out of bed. Historical Examples But, then, it was so early that not many even of the early-rising farmers were astir. Ruth Fielding In the Red Cross Alice B. Emerson The child was […]
American Society for Testing Materials. abbreviation American Society for Testing and Materials American Society for Testing and Materials