Source : Webster's Revised Unabridged Dictionary (1913)

Ametropia \Am`e*tro"pi*a\, n. [Gr. ? irregular + ?, ?, eye.]
   (Med.)
   Any abnormal condition of the refracting powers of the eye.
   -- {Am`e*trop"ic}, a.

Source : WordNet®

ametropia
     n : (ophthalmology) faulty refraction of light rays in the eye
         as in astigmatism or myopia