Participating children completed a 65-item questionnaire that included information about near-work factors, such as the amount of time spent in near work and outdoor activities and the duration of continuous reading (questionnaire available at http://www.cvr.org.au/sms.htm). Near-work activities included completing homework, reading for pleasure, playing musical instruments, using a computer, playing hand-held console games, and playing video games and board games. Watching television, videos, or digital video discs (DVDs) was classified as a midrange activity and was not included as near work. The total number of hours spent in near work per day was assessed for weekdays and weekends separately and was used to calculate the total time spent in near work each week. To assess the duration of continuous reading, children were asked about the time they spent in continuous reading or close work before taking a break of 5 minutes or longer. Outdoor activities included general activities (such as being in one’s own backyard, walking, or riding a bike or scooter), leisure activities (such as a barbeque, a picnic, spending time at the beach, or going for bush walks), and outdoor sport.
Parents completed a 173-item questionnaire, which collected sociodemographic data including ethnicity, level of education and occupation. Details of their child’s medical history and any developmental delay—for example, in achieving developmental milestones, or learning difficulties—were also ascertained. The questionnaire asked parents whether they thought their children held books close to the face during near-work activities, and if so, to estimate the working distance as 0 to <10 cm (0 to <4 in.), 10 to <20 cm (4 to <8 in.), 20 to <30 cm (8 to <12 in.), or unsure. Duplicate questions about the time children spent in near work and outdoor activities were included in the parents’ questionnaire, for corroboration of the students’ answers. To determine whether the parents had myopia, we asked whether they needed to use spectacles or contact lenses, the age at which they first used them, and the reason for using spectacles (for distance viewing only or near work only or for both distance viewing and near work). Spectacle prescriptions were obtained from parents or their prescribers when possible. If the prescriptions were not available, spectacle-use questions were used to decide whether the parents were myopic or nonmyopic.
32 Between 48% and 50% of parents in the study who answered the spectacle-use questions reported not using spectacles. Of all parents who were identified as myopic (436 mothers and 355 fathers), most (73.6% of mothers and 76.9% of fathers) were determined by the questionnaire data alone. Myopic prescriptions confirming questionnaire data were available for 26% and 23% of the mothers and fathers, respectively.