Could sending your child to a good school and making sure they do their homework be putting their eyesight in serious danger? That's the concern raised by research that reveals alarmingly strong links between time spent studying hard and childhood short-sightedness - myopia - that can lead to serious eye diseases.
Myopia causes distant objects to appear blurred, while close ones can be seen clearly. It often develops in childhood, with the eyeball starting to elongate, becoming more egg-shaped than spherical, or the lens becoming too curved, so the light entering the eye is not focused correctly.
It looks as if schoolwork might be a strong risk factor for myopia in children. In East Asia, where children are often academically hothoused from an early age, the rise in myopia is even greater.
The key to protecting your child may be as simple as ensuring they play outside as much as possible in the school holidays and after school. Children who did a lot of close-up academic work and spent most of their time indoors were more likely to become short-sighted.
Chinese school designers are busy with the attempt to tackle their country's rising myopia rate. In Guangdong province, for example, they have constructed bright-light classrooms with walls and ceilings made of see-through plastic. Two years ago, Taiwanese researchers got one school to lock its students out of the classroom during break-time and lunch. As a result, students had 80 minutes more sunlight during the school day.