asphericaladj.
/əsˈfɛrɪkəl//eɪsˈfɛrɪkəl/ = aspheric adj.
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the world > physical sensation > sight and vision > optical instruments > lens > [adjective] > types of lenses
convex?a1560
planoconvex1665
concavo-convex1677
convexo-concave1693
strong1732
aplanatic1799
periscopic1803
omphaloptic1819
polyzonal1823
shallow1837
first-order1846
periscopical1846
orthoscopic1853
rectilinear1874
overcorrected1875
sphero-cylindrical1881
wide-aperture1882
afocal1887
apochromatic1887
anastigmatic1890
telecentric1892
photovisual1899
aspherical1922
aspheric1923
multifocal1928
plano1944
demagnifying1959
1922 A. H. Levy tr. M. von Rohr Eyes & Spectacles ii. 75 We consider an aspherical surface [of a lens] to be formed by adding material to a spherical surface.
1923 R. Glazebrook Dict. Appl. Physics IV. 160/1 Aspherical lens, a type of spectacle lens designed to correct the aberration introduced when the eye looks towards the edge of the lens instead of to the centre.
This entry has not yet been fully updated (first published 1972; most recently modified version published online September 2018).
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adj.1922