Source : Webster's Revised Unabridged Dictionary (1913)

Eyeglass \Eye"glass`\, n.
   1. A lens of glass to assist the sight. Eyeglasses are used
      singly or in pairs.

   2. Eyepiece of a telescope, microscope, etc.

   3. The retina. [Poetic]

   4. A glass eyecup. See {Eyecup}.

Source : WordNet®

eyeglass
     n : lens for correcting defective vision in one eye; held in
         place by facial muscles [syn: {monocle}]