Education, reading, and familial tendency as risk factors for myopia in Hong Kong fishermen.

ABSTRACT

STUDY OBJECTIVE: The aim was to assess the influence of childhood reading on the development of myopia after allowance for familial differences in susceptibility. DESIGN: The study was a cross sectional survey. SETTING: Four fishing harbours in Hong Kong in 1989. SUBJECTS: Participants were 408 men and women aged 15-39 years old from 159 families. MAIN RESULTS: Histories of school attendance and reading habits in childhood were obtained at interview. Myopia was assessed by retinoscopy. Associations between myopia (defined as a refractive error of at least -1.0D in one or both eyes) and indices of reading in childhood were explored. Myopia was more common in subjects who had attended school (odds ratio = 1.7, 95% CI 1.0-3.0), with the highest risks in those who had started school at the earliest ages and who had spent the most time reading and writing while at primary school. Allowance for familial tendency to myopia produced no diminution in the risks associated with reading. CONCLUSIONS: These data support the hypothesis that reading in childhood is a cause of short sight.