Table 4 Overview of duration, time and mean number of daylight hours for the school holidays in Norwegian upper secondary school, including proportion of students who reported to spend half of the day or more than half of the day outdoors in these periods.
From: Prevalence and Possible Factors of Myopia in Norwegian Adolescents
Duration of holiday (time of the year) | Mean # daylight hours in the period | Proportion (%) | Proportions (%) who spend most time indoors | ||||
|---|---|---|---|---|---|---|---|
Spend half of the day outdoors | Spend more than half of the day outdoors | Myopes | Non-myopes | p-value | |||
Summer | 8 weeks (mid June–mid August) | 17 h 35 min | 45 | 49 | 14 | 4 | 0.007* |
Autumn | 1 week (October) | 11 h 5 min | 38 | 9 | 47 | 53 | 0.447 |
Winter | 1 week (February) | 10 h 36 min | 35 | 8 | 67 | 56 | 0.164 |
Spring (Easter) | 1.4 weeks (March–April) | 14 h 21 min | 52 | 12 | 41 | 35 | 0.428 |
