Ametropic amblyopia.

Hypermetropia of more than 5 diopters or an astigmatism of 2 diopters or more is often the cause of amblyopia in the master eye, independent of the presence of a simultaneous strabismus or anisometropia. This amblyopia can be prevented with early spectacle correction. In the authors' study of 218 patients with high ametropia a correlation was not always present between visual acuity and the age of the first spectacle correction or the degree of ametropia. In some patients even correction of ametropia as late as seven to ten years of age led to spontaneous functional improvement of single optotypes acuity. The treatment of choice is to give the full ametropic correction at an early age.