Anisometropia is the condition in which the two eyes have unequal refractive power; that is, are in different states of myopia (nearsightedness), hyperopia (farsightedness) or in the extreme, antimetropia (wherein one eye is myopic and the other is hyperopic), the unequal refractive states cause unequal rotations thus leading to diplopia.. Gross anisometropia is the difference of more than 2 diopters between the eyes.
Anisometropia can adversely affect the development of binocular vision in infants and children if there is a large difference in clarity between the two eyes. The brain will often suppress the vision of the blurrier eye in a condition called amblyopia, or lazy eye.
The name is from four Greek components: an- "not," iso- "same," metr- "measure," ops "eye."
One study estimated that 6% of those between the ages of 6 and 18 have anisometropia.
