Dictionary    Maps    Thesaurus    Translate    Advanced >   


Tip: Click Thesaurus above for synonyms. Also, follow synonym links within the dictionary to find definitions from other sources.

1. The Collaborative International Dictionary of English v.0.48
Lens \Lens\ (l[e^]nz), n.; pl. Lenses (-[e^]z). [L. lens a
   lentil. So named from the resemblance in shape of a double
   convex lens to the seed of a lentil. Cf. Lentil.] (Opt.)
   A piece of glass, or other transparent substance, ground with
   two opposite regular surfaces, either both curved, or one
   curved and the other plane, and commonly used, either singly
   or combined, in optical instruments, for changing the
   direction of rays of light, and thus magnifying objects, or
   otherwise modifying vision. In practice, the curved surfaces
   are usually spherical, though rarely cylindrical, or of some
   other figure.
   [1913 Webster] Lenses
   [1913 Webster]

   Note: Of spherical lenses, there are six varieties, as shown
         in section in the figures herewith given: viz., a
         plano-concave; b double-concave; c plano-convex; d
         double-convex; e converging concavo-convex, or
         converging meniscus; f diverging concavo-convex, or
         diverging meniscus.
         [1913 Webster]

   Crossed lens (Opt.), a double-convex lens with one radius
      equal to six times the other.

   Crystalline lens. (Anat.) See Eye.

   Fresnel lens (Opt.), a compound lens formed by placing
      around a central convex lens rings of glass so curved as
      to have the same focus; used, especially in lighthouses,
      for concentrating light in a particular direction; -- so
      called from the inventor.

   Multiplying lens or Multiplying glass (Opt.), a lens one
      side of which is plane and the other convex, but made up
      of a number of plane faces inclined to one another, each
      of which presents a separate image of the object viewed
      through it, so that the object is, as it were, multiplied.
      

   Polyzonal lens. See Polyzonal.
      [1913 Webster]

2. The Collaborative International Dictionary of English v.0.48
Polyzonal \Pol`y*zon"al\, a. [Poly- + zonal.]
   Consisting of many zones or rings.
   [1913 Webster]

   Polyzonal lens (Opt.), a lens made up of pieces arranged
      zones or rings, -- used in the lanterns of lighthouses.
      [1913 Webster]

Common Misspellings >
Most Popular Searches: Define Misanthrope, Define Pulchritudinous, Define Happy, Define Veracity, Define Cornucopia, Define Almuerzo, Define Atresic, Define URL, Definitions Of Words, Definition Of Get Up, Definition Of Quid Pro Quo, Definition Of Irreconcilable Differences, Definition Of Word, Synonyms of Repetitive, Synonym Dictionary, Synonym Antonyms. See our main index and map index for more details.

©2011-2024 ZebraWords.com - Define Yourself - The Search for Meanings and Meaning Means I Mean. All content subject to terms and conditions as set out here. Contact Us, peruse our Privacy Policy