What amount of hyperopia, or farsightedness, puts a child at risk for amblyopia?

According to revised guidelines published in 2012 by the American Association for Pediatric Ophthalmology and Strabismus (AAPOS), the amount of hyperopia that puts a child at risk for amblyopia varies according to age, since the amount of hyperopia normally naturally lessens as a child ages and his eyes grow. For children aged 12-30 months, AAPOS guidelines consider the child at risk for hyperopia greater than +4.5 diopters; for children aged 31-48 months, hyperopia greater than +4.0 diopters is considered a risk factor for amblyopia, and for children older than 49 months, farsightedness of more than +3.5 diopters is considered an amblyopia risk factor. iScreen Vision uses AAPOS guidelines in analyzing images and determining whether or not a child who is screened or tested for amblyopia should be referred for hyperopia.