Source : WordNet®

astigmia
     n 1: (ophthalmology) impaired eyesight resulting usually from
          irregular conformation of the cornea [syn: {astigmatism}]
     2: (optics) defect in an optical system in which light rays
        from a single point fail to converge in a single focal
        point [syn: {astigmatism}] [ant: {stigmatism}]