Characteristics of non-myopes, low myopes, and high myopes (Singapore National Servicemen 1998-9) (n=429)
| Non-myopes (>−0.5 dioptres) (n=51) | Low myopes (−0.5 to −5.9 dioptres) (n=164) | High myopes (at least −6.0 dioptres) (n=214) | Two sided p value | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| No (%) | No (%) | No (%) | ||||||||
| Age of first spectacle wear (years) (median, range) | 12 (7, 21) | 9 (4, 14) | <0.001 | |||||||
| Father's highest educational level | ||||||||||
| Primary or secondary | 42 (13.6) | 126 (40.9) | 140 (45.5) | 0.013 | ||||||
| Pre-university or tertiary | 8 (7.1) | 36 (31.9) | 69 (61.1) | |||||||
| Mother's highest education level | ||||||||||
| Primary or secondary | 44 (14.3) | 144 (46.8) | 170 (55.2) | 0.18 | ||||||
| Pre-university or tertiary | 4 (7.4) | 17 (31.5) | 33 (61.1) | |||||||
| Outdoor activity (hours per week) (median, range) | 10 (0,72) | 10 (0,72) | 8.5 (0, 59.5) | 0.069 | ||||||
| Outdoor activity at 7 years (hours per week) (median, range) | 10 (0,56) | 8.3 (0, 70) | 7.5 (0, 58.5) | 0.16 | ||||||
| Number of parents with myopia | ||||||||||
| None | 21 (13.6) | 77 (50.0) | 56 (36.4) | <0.001 | ||||||
| One | 11 (8.3) | 48 (36.1) | 74 (55.6) | (χ2 test | ||||||
| Two | 4 (4.8) | 21 (25.3) | 58 (69.9) | for trend) | ||||||
| Unknown | 15 (25.4) | 18 (30.5) | 26 (44.1) | |||||||