scotomy

from The Collaborative International Dictionary of English v.0.48

Scotomy \Scot"o*my\, n. [NL. scotomia, from Gr. ? dizziness, fr.
   ? to darken, fr. sko`tos darkness: cf. F. scotomie.]
   1. Dizziness with dimness of sight. [Obs.] --Massinger.
      [1913 Webster]

   2. (Med.) Obscuration of the field of vision due to the
      appearance of a dark spot before the eye.
      [1913 Webster]