| Refractive error (D) | ||||||
| Sleeping time | N | Prevalence rate | Unadjusted mean | 95%CI | Adjusted mean | 95%CI |
| (SD) | (SD) | |||||
| 9 hours or more | 5675 | 34.08% | −0.76 (1.82) | −0.81, −0.71 | −1.29 (0.03) | −1.36, −1.23 |
| About 8 hours | 4859 | 55.55% | −1.57 (3.23) | −1.67, −1.48 | −1.49 (0.02) | −1.54, −1.45 |
| 7 hours or less | 4567 | 68.03% | −2.28 (2.27) | −2.35, −2.21 | −1.69 (0.04) | −1.77, −1.62 |
| P (trend) | <0.001 | <0.001 | ||||
| Regression model results | ||||||
| Regression coefficient | −0.71 | −0.09 | ||||
| P (regression) | <0.001 | <0.001 | ||||