Table 1

 Refractive criteria based on the literature

Refractive errorNormal refractionBorderline refractive errorAbnormal refractive error
Clinically cylinder errors are recorded in minus cylinder form, hence the cylinder criteria are in minus values. A child’s refraction was categorised on the basis of the eye with the greatest error—for example, right +3.50/−1.00, left +3.50/−1.50 would be categorised as an abnormal refractive error on the basis of the left eye.
Hypermetropia<+3.00 DS+3.00 to < +4.00 DS⩾+4.00
Myopia<−1.00 DS−1.00 to −2.00 DS>−2.00 DS
Astigmatism<−1.00 DC−1.00 to <1.50 DC⩾−1.50 DC
Anisometropia<1.00 DS/DC<1.00 DS/DC⩾1.00 DS/DC