Participant characteristics | |
---|---|
Age (years) | n (%) |
5 | 1 (0.02%) |
6 | 292 (6.1%) |
7 | 345 (7.2%) |
8 | 359 (7.5%) |
9 | 369 (7.7%) |
10 | 360 (7.5%) |
11 | 385 (8.0%) |
12 | 353 (7.3%) |
13 | 374 (7.8%) |
14 | 365 (7.6%) |
15 | 371 (7.7%) |
16 | 361 (7.5%) |
17 | 370 (7.7%) |
18 | 370 (7.7%) |
19 | 121 (2.5%) |
20 | 5 (0.1%) |
Mean (SD) | 12.3 (3.8) |
Gender | |
Male | 2647 (55.1%) |
Female | 2154 (44.9%) |
Grade | |
Kindergarten | 381 (7.9%) |
Grade 1 | 331 (6.9%) |
Grade 2 | 366 (7.6%) |
Grade 3 | 371 (7.7%) |
Grade 4 | 367 (7.6%) |
Grade 5 | 376 (7.8%) |
Grade 6 | 368 (7.7%) |
Grade 7 | 376 (7.8%) |
Grade 8 | 360 (7.5%) |
Grade 9 | 346 (7.2%) |
Grade 10 | 383 (8.0%) |
Grade 11 | 373 (7.8%) |
Grade 12 | 403 (8.4%) |
School location | |
Urban | 2691 (56.1%) |
Rural | 2110 (43.9%) |
Spherical equivalent of more astigmatic eye (Diopters) | |
≤ −6 | 351 (7.3%) |
> −6, ≤ −5 | 267 (5.6%) |
> −5, ≤ −4 | 414 (8.6%) |
> −4, ≤ −3 | 510 (10.6%) |
> −3, ≤ −2 | 584 (12.2%) |
> −2, ≤ −1 | 768 (16.0%) |
> −1, ≤ −0.5 | 557 (11.6%) |
> −0.5, < 0.5 | 1076 (22.4%) |
≥ 0.5, < 1.0 | 171 (3.6%) |
≥ 1.0 | 103 (2.2%) |
Cylinder of more astigmatic eye (diopters) | |
0 | 204 (4.3%) |
> 0, < 0.5 | 952 (19.8%) |
≥ 0.5, < 1.0 | 2063 (43.0%) |
≥ 1.0, < 1.5 | 902 (18.8%) |
≥ 1.5, < 2.0 | 349 (7.3%) |
≥ 2.0, < 2.5 | 162 (3.4%) |
≥ 2.5, < 3.0 | 66 (1.4%) |
≥ 3.0, < 4.0 | 73 (1.5%) |
≥ 4.0 | 30 (0.6%) |
Mean (SD) | 0.87 (0.75) |
Median (1st quartile, 3rd quartile) | 0.75 (0.50, 1.12) |
Minimum, Maximum | 0, 15 |
Astigmatism ≥ 1.5 diopters | 680 (14.2%) |
With-the-rule | 575 (84.6%) |
Against-the-rule | 11 (1.62%) |
Oblique | 94 (13.8%) |
Astigmatism ≥ 3.0 diopters | 103 (2.15%) |
With-the-rule | 93 (90.3%) |
Against-the-rule | 2 (1.94%) |
Oblique | 8 (7.77%) |