The mystery of myopia.

Published data from all parts of the world show that myopia is rare before school age, gradually increases during school life and reaches its highest level of prevalence during the years of most intense study at university. It is widely held that continuous reading harms the eyes, but none of the attempts made so far to reduce accommodative fatigue by introducing pauses during reading and teaching, eye exercises, etc. have been successful in reducing the number of children who develop myopia. However, we should not exclude the possibility that the introduction into schools of better tables, better lighting, more breaks and more sport has not only benefited the general health of children, mentally as well as physically, but has also decreased the development and progression of myopia. More research in this area is needed, but relevant protocols are difficult to establish. The aetiology of myopia is multifactorial and both genes and environment play important roles. Twin studies indicate a strong genetic influence and a weak environmental impact, while extreme myopia prevalences among selected population groups (university students) point to the opposite.