trifocal
51tri- — ♦ Préfixe, du lat. et du gr. tri « trois », signifiant en chimie « trois atomes, molécules, éléments » : triacide, trinitrate. ● tri Préfixe, du latin ou du grec tri , trois. tri Préfixe, du lat. et du gr. tri , trois . ⇒TRI , élém. formant Élém …
52trifacial neuralgia — n TRIGEMINAL NEURALGIA * * * trifocal neuralgia trigeminal n …
53trigeminal neuralgia — n an intense paroxysmal neuralgia involving one or more branches of the trigeminal nerve called also tic douloureux * * * (tic douloureux) see neuralgia * * * severe, episodic pain in the area supplied by the trigeminal nerve, often precipitated… …
54bifocal lens — a lens with two principal focal lengths: the upper part of the lens gives a sharp image of distant objects and the lower part gives a sharp image of near objects, as when reading. Examples are bifocal spectacles, bifocal contact lenses, and… …
55omnifocal lens — a lens whose power increases continuously and regularly in a downward direction, thereby avoiding the discontinuity in field and power of a bifocal or trifocal lens. Called also progressive l …
56trifocals — tri·fo·cals (triґfo kəlz) trifocal glasses …
57trifocals — n. eyeglasses with trifocal lenses, eyeglasses having lenses with three focal lengths …
58triple — adj 1. treble, threefold, threesome, ternate, ternary, trinary, trinal, trine, triadic; tripartite, tripart ed, three part, tri state, three piece, three ply, three layer, trifocal, Genetics. trisomic, Bot. trispermous, Chem. triatomic, Chem.… …
59bifocal lens — a lens with two principal focal lengths: the upper part of the lens gives a sharp image of distant objects and the lower part gives a sharp image of near objects, as when reading. Examples are bifocal spectacles, bifocal contact lenses, and… …
60lens — n. 1) (in anatomy) the transparent crystalline structure situated behind the pupil of the eye and enclosed in a thin transparent capsule. It helps to refract incoming light and focus it onto the retina. See also: accommodation 2) (in optics) a… …
