释义 |
toric, a. (n.)|ˈtɔərɪk, ˈtɒrɪk| [f. tor-us + -ic.] Of or pertaining to a torus (see torus 4); having the form of a torus or a portion of one; spec. in Ophthalm., applied to a lens with one surface curved like part of a torus, the radius of curvature having a minimum value in one direction and a maximum value in the direction at right angles to it; also as n., such a lens.
1890Trans. Amer. Ophthalm. Soc. V. 708 Such toric surfaces are concave, and, when sunk in a plate of glass, afford typical examples of concavo-plane toric lenses. 1900Buch's Handbk. Med. Sc. I. 595 A concave spherical combined with a convex toric surface. 1954S. Duke-Elder Parsons' Dis. Eye (ed. 12) iv. 41 A regularly astigmatic surface is said to have a toric curvature. 1962L. S. Sasieni Princ. & Pract. Optical Dispensing x. 264 ‘Commercial’ torics of minus powers are usually transposed to the form which provides a plus cylinder. 1973Nature 21/28 Dec. 479/2 A toric segment of bore diameter d, generator circle diameter D and length s measured along the central axis. 1978J. Parr Introd. Ophthalmol. ii. 44/1 A cylindrical curvature can be combined with a spherical curvature in a lens which is then called a toric surfaced lens. In astigmatism the surface of the cornea is toric instead of spherical. |