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]