Source : Webster's Revised Unabridged Dictionary (1913)

Omphalopter \Om`pha*lop"ter\, Omphaloptic \Om`pha*lop"tic\, n.
   [Gr. ? the navel + ? one who looks, ? belonging to sight:
   cf.F. omphaloptre.]
   An optical glass that is convex on both sides. [Obs.]
   --Hutton.