Definitions of visual problems in children
| Disorder | Definition | |
|---|---|---|
| Amblyopia | ≥ 2-line difference in best corrected acuity and worse than 20/40 in 1 eye | |
| Binocular vision | ||
| Strabismus | Tropias > 10 D | |
| Reduced stereoacuity | > 100 arcsec | |
| Refractive errors | At 31–48 mo | At > 48 mo |
| Hyperopia (sph) | > 4.0 D | > 3.5 D |
| Astigmatism (cyl) | > 2.0 D | > 1.5 D |
| Anisometropia (SE) | > 2.0 D IOD | > 1.5 D IOD |
| Myopia (sph) | < −2.0 D | < −1.5 D |
| Other problems | Nystagmus, vitreous abnormalities, optic nerve abnormalities | |
Note: cyl = cylindrical error, D = diopters, IOD = interocular difference, SE = spherical equivalent, sph = spherical error.