Source : Webster's Revised Unabridged Dictionary (1913)

Anisometropia \An`i*so*me*tro"pi*a\, n. [NL., fr. Gr. ? + ?
   measure + ?, ?, eye.]
   Unequal refractive power in the two eyes.

Source : WordNet®

anisometropia
     n : difference in the refractive power of the two eyes